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Periprosthetic fracture (tuhod)

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Updated Sep 2026
Illustration: knee

Ang pahinang ito ay isinalin ng makina at hindi pa nasusuri ng isang doktor. Ang bersyong Ingles ang siyang opisyal.

Ang iyong nararamdaman

Ang fracture sa paligid ng knee replacement ay nangangahulugang nabali ang buto malapit sa implant. Ang sakit ay karaniwang nararamdaman sa itaas o ibaba lamang ng tuhod, sa ibabang bahagi ng hita o sa itaas na bahagi ng shin. Madalas itong matalas sa simula at kalaunan ay nagiging isang malalim na kirot. Ang pagtayo, paglalakad, at pagbaluktot ng tuhod ay karaniwang nagpapalala rito. Ang pagpapahinga habang may suporta ang binti ay karaniwang nakakabawas ng sakit.

Ang sakit ay maaaring lumala sa gabi at kapag nagsisimula ka nang gumalaw pagkatapos maupo o humiga. Maraming tao ang mas nakapapansin nito kapag sila ay nagising at humahakbang sa unang pagkakataon. Ang pagbangon mula sa upuan, pag-akyat sa hagdan, paglalakad patungo sa letterbox, at pagpasok at paglabas ng kotse ay maaaring maging mahirap. Maaaring hindi ka magtiwala na kaya kang suportahan ng binti, kaya iniiwasan mong ilagay ang buong bigat dito.

Ang ganitong uri ng bali ay maaaring makaapekto sa iyo nang higit pa sa panahon ng paggaling. Ang kalidad ng buhay ay maaaring manatiling mababa hanggang 12 buwan pagkatapos ng pinsala, kahit na ang fracture mismo ay naghilom na. Ito ay isang normal na pattern, at hindi senyales na may mali sa iyong paggaling.

Ang mga fracture na ito ay madalas mangyari sa mga nakatatanda na ang mga buto ay hindi na kasingtibay ng dati. Hindi ito karaniwan, ngunit kapag nangyari, kailangan nito ng maingat na paggamot. Susuriing mabuti ng iyong surgeon ang iyong mga x-ray at kukuha ng kumpletong history upang alisin ang posibilidad ng impeksyon sa paligid ng replacement bago planuhin ang gagawin. Karamihan sa mga fracture na ito ay maaaring gamutin sa pamamagitan ng pagpapanatiling hindi gumagalaw ng buto habang ito ay naghihilom, habang ang knee replacement mismo ay nananatili sa pwesto. Ang operasyon upang palitan ang implant ay isinasaalang-alang lamang kapag ang implant ay lumuwag o nawala sa linya.

Ano ang aktwal na nangyayari

Ang isang knee replacement ay nakalagay sa loob ng buto gaya ng isang rod na nakabaon sa poste ng bakod. Matibay ang bahaging metal, ngunit ang buto sa paligid nito ang nagpapanatiling matatag sa lahat. Sa isang periprosthetic fracture, ang nakapalibot na butong iyon ang nagkakaroon ng lamat habang ang replacement mismo ay nananatili sa puwesto. Ang bali ay karaniwang nangyayari sa itaas lang ng replacement sa ibabang bahagi ng buto sa hita, o sa ibaba lang nito sa itaas na bahagi ng shin bone.

Ang mga baling ito ay may tendensiyang mangyari sa butong naging mas manipis at mas mahina sa paglipas ng panahon. Ang ilang kondisyong pangkalusugan at pangmatagalang pag-inom ng steroid tablets ay maaari ring magdulot upang ang buto ay maging hindi gaanong kakayanin na hawakan nang matatag ang isang implant. Minsan, ang buto malapit sa replacement ay dahan-dahang napupudpod, kaya mas kakaunti ang natitira upang dalhin ang bigat. Kapag ang mahinang buto ay nakaranas ng pagkatisod o pagkahulog, maaari itong magkaroon ng lamat kung saan ang mas matibay na buto ay hindi mababali.

Ang sakit na iyong nararamdaman ay mula sa bahagyang paggalaw ng nabaling buto sa tuwing binibigatan mo ang binti. Ang pagtayo at paglalakad ay nagdidikit sa mga naglalamat na gilid, kaya ang mga paggalaw na iyon ang pinakamasakit. Maaari ring maramdamang hindi matatag ang tuhod dahil ang butong humahawak sa replacement ay hindi na gumagalaw bilang isang buong piraso kasama ang nalalabing bahagi ng binti.

Susuriing mabuti ng iyong surgeon ang iyong mga x-ray, dahil ang metal ng replacement ay maaaring magtago ng break line sa isang plain film. Kung hindi malinaw ang mga x-ray, maaaring ipakita ito ng isang bone scan. Ang mga fracture na ito ay hindi karaniwan, nangyayari lamang sa maliit na porsyento ng mga knee replacement, ngunit kailangan ng maingat na paggamot kapag nangyari ang mga ito. Karamihan ay maaaring gamutin sa pamamagitan ng pagpapanatiling hindi gumagalaw ng buto habang ito ay gumagaling, habang hinahayaan ang replacement sa puwesto nito. Ang pagpapalit ng implant mismo ay isinasaalang-alang lamang kapag ito ay lumuwag o hindi na nakalinya nang tama.

Ano ang maaari naming gawin tungkol dito

Dahil ang bali na tulad nito ay isang structural injury, karaniwang inirerekomenda agad ang operasyon sa halip na sumubok muna ng non-operative care. Ang pagpapahintulot sa buto na gumaling nang kusa ay bihirang maging opsyon para sa mga fracture na ito. Ang karaniwang layunin ay panatilihing hindi gumagalaw ang nabaling buto habang ito ay gumagaling, habang nananatili sa pwesto ang iyong knee replacement. Bago ang anumang operasyon, maingat naming sinusuri kung may impeksyon sa paligid ng replacement, dahil binabago nito ang aming gagawin.

Ang pangunahing operasyon ay tinatawag na open reduction and internal fixation, na nangangahulugang ibinabalik ang buto sa tamang linya at pinapanatili doon gamit ang isang metal plate at mga screw. Para sa mga bali sa itaas lang ng replacement sa thigh bone, madalas na ginagamit ang isang locking plate. Ang mga screw nito ay nagla-lock sa mismong plate, na nagbibigay ng mas matatag na kapit sa mas manipis na buto. Ang isa pang opsyon para sa ilang thigh fractures ay isang rod na inilalagay sa loob ng bone canal. Ang parehong approach ay humahawak sa buto habang ito ay gumagaling, at pag-uusapan namin kung alin ang angkop sa iyong fracture.

Para sa mga bali sa ibaba lang ng replacement sa shin bone, ang plate ay maaari kung minsan na i-slide papasok sa pamamagitan ng dalawang maliliit na hiwa sa halip na isang mahabang opening. Pinapanatili nitong hindi nagagalaw ang nabaling bahagi, na nagpoprotekta sa blood supply na kailangan ng buto upang gumaling. Sa ilang kaso kung saan ang buto ay napakanipis, maaaring gumamit ng external frame sa halip. Pinapanatili nito ang katatagan ng buto mula sa labas ng binti.

Kung ang buto sa paligid ng replacement ay napudpod o nadurog sa bahagi ng bali, maaaring walang sapat na matigas na buto na natira para kumapit ang plate. Ang mga opsyon sa oras na ito ay kinabibilangan ng pagdaragdag ng donor bone upang suportahan ang repair, o pagpapalit ng ibabang bahagi ng thigh bone ng isang bagong implant. Ang huling opsyon ay isang mas malaking operasyon, ngunit pinapayagan ka nitong maglagay ng weight sa binti agad.

Ang maliit na bilang ng mga fracture na ito ay kinasasangkutan ng kneecap. Ang mga ito ay karaniwang ginagamot nang walang operasyon, sa pamamagitan ng pahinga at suporta habang bumabalik sa ayos ang buto.

Pagkatapos ng operasyon, ang paggalaw at muscle work ay karaniwang nagsisimula nang maaga, madalas sa loob ng unang dalawang araw. Gagamit ka ng crutches sa simula at maglalagay ng partial weight sa binti kapag pinahintulutan na ng sakit. Ang full weight ay pinapayagan kapag ang buto ay nagdugtong na, na sinusuri namin sa x-ray. Pag-uusapan namin ang iyong sariling plano kasama ka bago ka umuwi.

Ano ang dapat asahan

Ang mga bali na ito ay isang malaking sagabal, at nakatutulong ang pagharap dito nang may malinaw na pananaw. Karamihan ay ginagamot sa pamamagitan ng pagpapanatiling hindi gumagalaw ng buto habang ito ay gumagaling, habang nananatili sa pwesto ang iyong knee replacement. Kapag nagawa ito nang maayos, karaniwang nagdurugtong ang buto at patuloy na gumagana ang replacement. Pagkatapos ng karagdagang operasyon, 89 sa bawat 100 katao na may ganitong uri ng bali ay gumaling. Gayunpaman, hindi lahat ng bali ay nagdurugtong sa itinakdang oras. Ang ilang mga buto ay mabagal magdugtong, at may maliit na bilang na hindi kailanman nagdurugtong. Humigit-kumulang 18 sa bawat 100 katao na ginamot gamit ang plate para sa baling ito ang nagkaroon ng butong nabigong magdugtong, at mga 24 sa bawat 100 ang nagkaroon ng anumang uri ng komplikasyon sa proseso.

Ang paggaling ay inaabot ng mga buwan, hindi linggo. Para sa mga butong nangangailangan ng dagdag na tulong upang magdugtong, ang pagdurugtong ay nakitang nangyayari mula 3 hanggang 8 buwan. Hindi ka agad babalik sa normal, at mahalagang malaman ito ngayon. Kahit na ang bali mismo ay maayos na, ang epekto nito sa iyong kalidad ng buhay ay maaaring manatili hanggang 12 buwan. Maraming tao ang nakapapansin na mas madaling mapagod ang binti, ang pag-akyat sa hagdan ay nangangailangan ng pagpaplano, at ang tiwala sa tuhod ay dahan-dahang bumabalik. Iyan ang karaniwang takbo ng paggaling, at hindi senyales na may pumalyang proseso.

Mayroong ilang mga tunay na positibong aspeto. Kapag nagdugtong na ang buto, ang knee replacement mismo ay may tendensiyang manatiling gumagana nang kasinghusay ng dati. Ang mga taong may ganitong bali ay walang mas malalang replacement survival kumpara sa mga taong hindi kailanman nagkaroon nito. Ang ilang mga opsyon sa paggamot ay nagpapahintulot din sa iyo na maglagay ng bigat sa binti agad-agad, na maaaring mangahulugan ng mas maikling pananatili sa ospital at mas mabilis na pagbabalik sa mga pang-araw-araw na aktibidad.

Kung hahayaan lamang ang buto, bihira itong gumaling nang kusa, kaya naman karaniwang pinapayuhan ang maagang operasyon. Ang mga pangunahing panganib na dapat bantayan ay ang pagkabigo ng buto na magdugtong o ang pangangailangan ng karagdagang operasyon sa hinaharap para sa pagkukumpuni. Tatalakayin ng iyong surgeon kung paano nailalapat ang mga pigurang ito sa iyong sariling bali, sa kalidad ng iyong buto, at sa iyong pangkalahatang kalusugan.

Kailan dapat magpatingin

Kung ikaw ay matumba o madapa at makaramdam ng matalas na sakit sa itaas o ibaba lamang ng iyong knee replacement, ipasuri ito agad. Pumunta sa emergency department kung hindi mo kayang ilagay ang bigat sa binti kahit kaunti, o kung ang binti ay mukhang wala sa porma o umikli. Magpatingin agad sa iyong GP kung mayroong nananatiling sakit malapit sa replacement na hindi nawawala sa pamamagitan ng pahinga, o sakit na gumigising sa iyo sa gabi. Humingi ng specialist review kung ang tuhod ay pakiramdam na hindi matatag, o kung hindi mo mapagkatiwalaan ang binti na suportahan ka kapag nakatayo. Ang mga bali na ito ay nangyayari sa butong naging mas manipis at mas mahina, kaya ang isang maliit na pagkatisod ay maaaring sapat na. Kung may matagpuang bali, karaniwang pinapayuhan ang maagang operasyon, dahil bihirang gumaling ang buto nang kusa.

Reviewed by AI synthesis (v2) — pending human review · 9 September 2026.

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Evidence & references

This is the clinical evidence summary written for health professionals. It is technical, and it lists the research this page was built from. You do not need to read it to understand your treatment or to make a decision about it.

Anatomy & Pathophysiology

Bony Anatomy

  • The bones of the knee are the distal femur, the proximal tibia, and the patella [1].
  • The medial femoral condyle is larger and projects farther posteriorly and distally than the lateral condyle [4].
  • The lateral femoral condyle projects farther anteriorly and is wider in the medial-lateral direction than the medial femoral condyle [4].
  • The tibial articular surface slopes 7° to 10° in the sagittal plane [4].
  • The posterior slope of the medial tibial plateau averages 10.7° and the lateral plateau averages 7.2° [9].
  • The medial tibial plateau is larger than the lateral plateau and is concave in its frontal and sagittal planes [4].
  • The lateral tibial plateau is smaller, more circular, concave in the frontal plane, and convex in the sagittal plane [4].
  • The patella is the largest sesamoid bone in the body with a mean thickness of 2.5 cm [4, 9].
  • The patellar articular surface contains a vertical central ridge separating the broader lateral facet from the medial facet, and a smaller medial odd facet [4].
  • The fibular head is located a mean of 1.5 cm distal to the joint line, with a range of 6 to 32 mm [9].

Ligaments

  • The anterior cruciate ligament (ACL) prevents anterior translation and rotation of the tibia on the femur [1].
  • The posterior cruciate ligament (PCL) prevents posterior subluxation of the tibia on the femur [1].
  • The medial collateral ligament (MCL) stabilizes the knee to valgus stresses [1].
  • The lateral collateral ligament (LCL) is the main stabilizer against varus stress [1].
  • The ACL is composed of 90% type I collagen and 10% type III collagen [4, 9].
  • The mean length of the ACL is 33 mm and the mean midsubstance width is 11 mm [4, 9].
  • The femoral attachment of the ACL is a semicircular area on the posteromedial aspect of the lateral femoral condyle [4, 9].
  • The tibial attachment of the ACL is a broad, irregular, oval-shaped area between the medial and lateral tibial spinous processes [4, 9].
  • The anteromedial bundle of the ACL is tight in knee flexion and the posterolateral bundle is tight in knee extension [9].
  • The PCL has a mean length of 38 mm and a mean width of 13 mm [9, 17].
  • The PCL femoral footprint is a broad, semicircular attachment on the anterolateral aspect of the medial femoral condyle [9, 17].
  • The PCL tibial insertion is located 10 to 15 mm distal to the joint line on the posterior tibia [9, 17].
  • The anterolateral bundle of the PCL is larger and comprises 85% of the PCL's cross-sectional area [17].
  • The popliteofibular ligament is present in 90% of knees and runs from the popliteus tendon to the posterior fibular head [1].
  • The posterolateral corner (PLC) consists of the fibular collateral ligament, iliotibial band, popliteofibular ligament, biceps femoris, and popliteus tendon [14].

Menisci

  • The menisci are C-shaped fibrocartilaginous disks that provide shock absorption, increase joint congruency, enhance stability, and aid in synovial fluid distribution [1].
  • The medial meniscus is firmly attached to the joint capsule along its entire peripheral edge [1].
  • The lateral meniscus is attached to the anterior and posterior capsule but has a region posterolaterally where it is not firmly attached [1].
  • The medial meniscus has less mobility than the lateral meniscus and is more susceptible to tearing when trapped between the femoral condyle and tibial plateau [1].
  • The lateral meniscus is larger than the medial meniscus and carries a greater share of the lateral compartment pressure [1].
  • The medial meniscus has a mobility of 5 mm and the lateral meniscus has a mobility of 10 mm [9].
  • Vascular supply to the menisci penetrates into 20% to 30% of the peripheral medial meniscus and 10% to 25% of the peripheral lateral meniscus [9].

Vascular and Nerve Anatomy

  • The blood supply to the knee is formed from an anastomosis including the descending geniculate artery, superior and inferior geniculate arteries, middle geniculate artery, and anterior tibial recurrent arteries [4].
  • The middle geniculate artery supplies both the anterior and posterior cruciate ligaments [4].
  • The knee is innervated by branches of the femoral nerve (L2, L3, L4), obturator nerve (L2, L3, L4), and sciatic nerve (L4, L5, S1, S2) [4].
  • The posterior articular branch of the tibial nerve is the largest nerve providing innervation to the intra-articular knee [4].
  • The popliteal artery travels through the adductor hiatus where it is relatively immobile and distally through the fibrous arch deep to the soleus muscle [14].
  • The common peroneal nerve travels along the posterior edge of the biceps femoris and continues distally around the fibular neck [14].

Kinematics

  • The knee is a hinge joint that incorporates both gliding and rolling motions [5, 6].
  • The "screw-home" mechanism involves the tibia externally rotating 5 degrees in the final 15 degrees of extension [5, 6].
  • The greatest range of motion occurs in the sagittal plane at approximately 160° [21].
  • Knee rotation ranges from 45° in external rotation to 30° in internal rotation [21].
  • In the frontal plane, the range of motion in both abduction and adduction reaches a maximum of 10° [21].
  • During walking, knee range of motion reaches approximately 70° in the sagittal plane, 15° in the frontal plane, and 10° in the transverse plane [21].
  • The normal instant center of the knee joint follows a semicircular path related to the tibiofemoral surface and ligaments [21].
  • Rupture of the cruciate ligaments or disruption of the tibiofemoral surface causes a major change in the path of the instant center, leading to articular dysfunction [21].
  • In full extension, the knee slightly hyperextends with slight tibial external rotation while collateral and cruciate ligaments tighten to lock the knee [22].
  • The popliteus muscle initiates flexion by pulling the lateral femoral condyle backward while the medial femoral condyle slides forward, resulting in tibial internal rotation [22].

Periprosthetic Fracture Pathophysiology

  • The incidence of periprosthetic fracture of the distal femur in total knee arthroplasty is 0.3% to 2.5% [31].
  • The incidence of periprosthetic tibial fracture in primary total knee arthroplasty is 0.7% or less [31].
  • Anterior femoral notching during femoral preparation weakens the anterior femur at the bone-component interface [31].
  • Notching decreases the fracture resistance of the distal femur but does not necessarily equate to a higher risk of supracondylar femur fracture [31].
  • Risk factors for periprosthetic distal femur fracture include rheumatoid arthritis, neurologic disorders, chronic steroid therapy, osteopenia or osteoporosis, and osteolysis with bone loss [31].
  • Risk factors for periprosthetic tibial fracture include insertion of a long-stem component, a loose tibial component, periprosthetic osteolysis, malalignment of components, component removal during revision, and tibial tubercle osteotomy [31].
  • The fracture line in periprosthetic fractures may be obscured by a metallic component on plain radiographs [31].

Investigations

Plain Radiography

  • Plain radiographs are appropriate initial imaging studies for most knee conditions, allowing assessment of traumatic injury, arthritis, patellofemoral alignment, osteochondral injury, bone neoplasm, and surgical implants [3].
  • Imaging studies should include at least two perpendicular views: AP and lateral [3].
  • Weight-bearing AP (extension) views are used to assess cartilage loss from the distal femur and tibial plateau [3].
  • Weight-bearing PA (Rosenberg; flexion) views are used to assess cartilage loss from the posterior femur and tibial plateau [3].
  • Patellofemoral views are used to assess patellofemoral alignment, patellar and trochlear morphology, osteochondral injury, and patellofemoral arthritis [3].
  • Notch views are used to assess posterior femoral cartilage, notch width, and osteophytes [3].
  • Non-weight-bearing radiographs may identify acute injury without the risk of fracture displacement [3].
  • Radiography may identify subchondral sclerosis, joint space narrowing, subchondral cysts, osteophytes, and joint subluxation in osteoarthritis [3].
  • Radiography may identify linear radiolucency or radiodensity in stress fractures, most commonly in the proximal medial tibia [3].
  • Radiography may identify a mixed sclerotic pattern with a subchondral, epiphyseal, or metaphyseal location in osteonecrosis [3].
  • Supine AP knee radiographs do not adequately estimate the joint space width needed to estimate the degree of osteoarthritis progression [27].
  • A 45° standing flexion view was introduced to better evaluate joint space due to inaccuracies in plain frontal radiographs [27].
  • The fixed flexion view (FFV) technique uses a 10° caudal irradiation angle and fixed limb position for improved reproducibility and joint space evaluation [27].
  • The Lyon Schuss view (LSV) requires fluoroscopic adjustment of the irradiation angle relative to the medial tibial plateau for more accurate joint space width measurement but involves higher radiation exposure and complex positioning [27].
  • Goniometer readings of long limb alignment or measured on an FFV correlate well with angles measured on long limb radiographs, providing an alternative if long limb radiographs are not available [27].
  • The Kellgren-Lawrence (KL) classification grades osteoarthritis severity from 0 to 4 based on AP knee radiograph features including osteophytes and joint space narrowing [23].
  • Knee arthroplasty is recommended when KL Grade 4 findings are present [23].

Computed Tomography

  • CT provides enhanced bone detail through a three-dimensional study performed with ionizing radiation [3].
  • CT imaging in axial, sagittal, and coronal planes helps visualize fracture lines, displacement, osteolytic lesions around joint arthroplasty, and cortical disruption in infection or neoplasia [3].
  • Three-dimensional CT reconstructions may help with preoperative planning for complex intra-articular fractures, multiplanar osteotomy for limb malalignment, and reconstitution of bone loss in joint arthroplasty [3].
  • Axial plane CT imaging of the knee can help assess the rotational alignment of components of a total knee arthroplasty in cases of patellar maltracking [3].
  • Three-dimensional CT with remodeling is used for preoperative planning for reconstruction associated with dysplasia, post-trauma planning, and complex total knee arthroplasty planning [23].

Magnetic Resonance Imaging

  • MRI may help assess overall limb alignment and further delineate intra-articular and extra-articular soft tissues, including cartilage, menisci, ligaments, tendons, muscles, and nerve and vascular structures [3].
  • MRI findings of edema, intra-articular fluid, disruption of ligament fibers, and atypical ligament contour may suggest cruciate ligament injury [3].
  • MRI can identify patterns of meniscal injury by location, pattern (horizontal, longitudinal, radial, complex), and displacement [3].
  • MRI may identify the degree of articular cartilage injury, associated bone marrow edema, and lesion location [3].
  • MRI may identify edema, avulsion, or discontinuity for extra-articular ligaments such as the MCL/LCL or associated posteromedial and posterolateral ligamentous complexes [3].
  • MRI may be used to assess the continuity of the quadriceps or patellar tendon [3].
  • MRI may be used to assess neurovascular structures, including the margin of resection for a neoplasm, vascular malformation, or location of nerves relative to popliteal cysts [3].
  • MRI is the most useful study for differentiating osteonecrosis from other conditions such as osteochondritis dissecans, transient osteoporosis, bone bruises, or occult fractures [29].
  • A serpentine lesion within a well-demarcated border is a specific finding on MRI for osteonecrosis [29].
  • MRI is not indicated if the joint space is significantly narrowed on radiograph in the arthritic patient population [23].
  • MRI is used when osteonecrosis is suspected in the arthritic patient population [23].

Nuclear Medicine

  • Increased radionuclide activity in bone may be a normal postoperative finding for up to 6 to 12 months after a fracture repair or arthroplasty [3].
  • Technetium-99 (Tc-99) may help identify infection, neoplasia, occult fracture, bone healing, active phases of heterotopic ossification, implant loosening, or failure of osseointegration [3].
  • Gallium-67 (Ga-67) may help differentiate between aseptic and septic prosthetic loosening, requiring 24 to 72 hours for a complete study [3].

General Assessment

  • Radiographic studies help confirm the clinical diagnosis of a joint disorder determined using the patient’s history and physical examination [3].
  • Physical examination along with radiographic or advanced imaging findings must be used concomitantly to determine the source of symptoms and appropriate surgical intervention [7].
  • Assessment of the joint must combine physical examination along with radiographic (including full-length alignment views) and MRI findings for cartilage injury [30].

References

[1] A Lange Medical Book Current Diagnosis Treatment In Orthopedics Fifth Edition. 3Sports Medicine > Image KNEE INJURIES.

[3] Aaos Comprehensive Orthopaedic Review 3. Radiographic Evaluation and Surgical Anatomy of the Knee > I. Radiographic Evaluation.

[4] Aaos Comprehensive Orthopaedic Review 3. Anatomy and Biomechanics of the Knee > I. Anatomy.

[5] Miller S Review Of Orthopaedics. SECTION 16 PATELLAR TRACKING IN TOTAL KNEE ARTHROPLASTY > SECTION 1 KNEE > ANATOMY (FIG. 4.1).

[6] Miller S Review Of Orthopaedics. SECTION 1 KNEE > ANATOMY (FIG. 4.1).

[7] Orthopaedic Knowledge Update 13 Ebook Without Multimedia. Knee Arthroscopy and Preservation, Knee Reconstruction > Introduction.

[9] Aaos Comprehensive Orthopaedic Review 3. Radiographic Evaluation and Surgical Anatomy of the Knee > II. Surgical Anatomy of the Knee.

[14] Aaos Comprehensive Orthopaedic Review 3. Knee Dislocations and Patellar Fractures* > I. Knee Dislocations.

[17] Rockwood And Green S Fractures In Adults. 59: Patellar Fractures and Dislocations and Extensor Mechanism Injuries > Posterior Knee Anatomy.

[21] Aaos Comprehensive Orthopaedic Review 3. Biomechanics and Wear in Joint Arthroplasty > III. The Knee Joint.

[22] Orthopaedic Knowledge Update 13 Ebook Without Multimedia. Knee Anatomy > Knee Kinematics.

[23] Miller S Review Of Orthopaedics. SECTION 16 PATELLAR TRACKING IN TOTAL KNEE ARTHROPLASTY > SECTION 11 KNEE ARTHRITIS ASSESSMENT.

[27] Orthopaedic Knowledge Update 13 Ebook Without Multimedia. Knee Anatomy > Imaging (Radiograph, MRI, CT Scan, Dynamic Versus Static) > Radiograph.

[29] Aaos Comprehensive Orthopaedic Review 3. General Evaluation of the Knee Patient > III. Osteonecrosis.

[30] Orthopaedic Knowledge Update 13 Ebook Without Multimedia. Knee Arthroscopy and Preservation, Knee Reconstruction > Summary.

[31] Aaos Comprehensive Orthopaedic Review 3. Periprosthetic Fractures Associated With Total Hip and Knee Arthroplasty > II. Total Knee Arthroplasty.

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Considerations for the public: By using one of our public licenses, a licensor grants the public permission to use the licensed material under specified terms and conditions. If the licensor's permission is not necessary for any reason--for example, because of any applicable exception or limitation to copyright--then that use is not regulated by the license. Our licenses grant only permissions under copyright and certain other rights that a licensor has authority to grant. Use of the licensed material may still be restricted for other reasons, including because others have copyright or other rights in the material. A licensor may make special requests, such as asking that all changes be marked or described. Although not required by our licenses, you are encouraged to respect those requests where reasonable. More considerations for the public: wiki.creativecommons.org/Considerations_for_licensees

Creative Commons Attribution-NonCommercial 4.0 International Public License

By exercising the Licensed Rights (defined below), You accept and agree to be bound by the terms and conditions of this Creative Commons Attribution-NonCommercial 4.0 International Public License ("Public License"). To the extent this Public License may be interpreted as a contract, You are granted the Licensed Rights in consideration of Your acceptance of these terms and conditions, and the Licensor grants You such rights in consideration of benefits the Licensor receives from making the Licensed Material available under these terms and conditions.

Section 1 -- Definitions.

a. Adapted Material means material subject to Copyright and Similar Rights that is derived from or based upon the Licensed Material and in which the Licensed Material is translated, altered, arranged, transformed, or otherwise modified in a manner requiring permission under the Copyright and Similar Rights held by the Licensor. For purposes of this Public License, where the Licensed Material is a musical work, performance, or sound recording, Adapted Material is always produced where the Licensed Material is synched in timed relation with a moving image.

b. Adapter's License means the license You apply to Your Copyright and Similar Rights in Your contributions to Adapted Material in accordance with the terms and conditions of this Public License.

c. Copyright and Similar Rights means copyright and/or similar rights closely related to copyright including, without limitation, performance, broadcast, sound recording, and Sui Generis Database Rights, without regard to how the rights are labeled or categorized. For purposes of this Public License, the rights specified in Section 2(b)(1)-(2) are not Copyright and Similar Rights.

d. Effective Technological Measures means those measures that, in the absence of proper authority, may not be circumvented under laws fulfilling obligations under Article 11 of the WIPO Copyright Treaty adopted on December 20, 1996, and/or similar international agreements.

e. Exceptions and Limitations means fair use, fair dealing, and/or any other exception or limitation to Copyright and Similar Rights that applies to Your use of the Licensed Material.

f. Licensed Material means the artistic or literary work, database, or other material to which the Licensor applied this Public License.

g. Licensed Rights means the rights granted to You subject to the terms and conditions of this Public License, which are limited to all Copyright and Similar Rights that apply to Your use of the Licensed Material and that the Licensor has authority to license.

h. Licensor means the individual(s) or entity(ies) granting rights under this Public License.

i. NonCommercial means not primarily intended for or directed towards commercial advantage or monetary compensation. For purposes of this Public License, the exchange of the Licensed Material for other material subject to Copyright and Similar Rights by digital file-sharing or similar means is NonCommercial provided there is no payment of monetary compensation in connection with the exchange.

j. Share means to provide material to the public by any means or process that requires permission under the Licensed Rights, such as reproduction, public display, public performance, distribution, dissemination, communication, or importation, and to make material available to the public including in ways that members of the public may access the material from a place and at a time individually chosen by them.

k. Sui Generis Database Rights means rights other than copyright resulting from Directive 96/9/EC of the European Parliament and of the Council of 11 March 1996 on the legal protection of databases, as amended and/or succeeded, as well as other essentially equivalent rights anywhere in the world.

l. You means the individual or entity exercising the Licensed Rights under this Public License. Your has a corresponding meaning.

Section 2 -- Scope.

a. License grant.

1. Subject to the terms and conditions of this Public License, the Licensor hereby grants You a worldwide, royalty-free, non-sublicensable, non-exclusive, irrevocable license to exercise the Licensed Rights in the Licensed Material to:

a. reproduce and Share the Licensed Material, in whole or in part, for NonCommercial purposes only; and

b. produce, reproduce, and Share Adapted Material for NonCommercial purposes only.

2. Exceptions and Limitations. For the avoidance of doubt, where Exceptions and Limitations apply to Your use, this Public License does not apply, and You do not need to comply with its terms and conditions.

3. Term. The term of this Public License is specified in Section 6(a).

4. Media and formats; technical modifications allowed. The Licensor authorizes You to exercise the Licensed Rights in all media and formats whether now known or hereafter created, and to make technical modifications necessary to do so. The Licensor waives and/or agrees not to assert any right or authority to forbid You from making technical modifications necessary to exercise the Licensed Rights, including technical modifications necessary to circumvent Effective Technological Measures. For purposes of this Public License, simply making modifications authorized by this Section 2(a) (4) never produces Adapted Material.

5. Downstream recipients.

a. Offer from the Licensor -- Licensed Material. Every recipient of the Licensed Material automatically receives an offer from the Licensor to exercise the Licensed Rights under the terms and conditions of this Public License.

b. No downstream restrictions. You may not offer or impose any additional or different terms or conditions on, or apply any Effective Technological Measures to, the Licensed Material if doing so restricts exercise of the Licensed Rights by any recipient of the Licensed Material.

6. No endorsement. Nothing in this Public License constitutes or may be construed as permission to assert or imply that You are, or that Your use of the Licensed Material is, connected with, or sponsored, endorsed, or granted official status by, the Licensor or others designated to receive attribution as provided in Section 3(a)(1)(A)(i).

b. Other rights.

1. Moral rights, such as the right of integrity, are not licensed under this Public License, nor are publicity, privacy, and/or other similar personality rights; however, to the extent possible, the Licensor waives and/or agrees not to assert any such rights held by the Licensor to the limited extent necessary to allow You to exercise the Licensed Rights, but not otherwise.

2. Patent and trademark rights are not licensed under this Public License.

3. To the extent possible, the Licensor waives any right to collect royalties from You for the exercise of the Licensed Rights, whether directly or through a collecting society under any voluntary or waivable statutory or compulsory licensing scheme. In all other cases the Licensor expressly reserves any right to collect such royalties, including when the Licensed Material is used other than for NonCommercial purposes.

Section 3 -- License Conditions.

Your exercise of the Licensed Rights is expressly made subject to the following conditions.

a. Attribution.

1. If You Share the Licensed Material (including in modified form), You must:

a. retain the following if it is supplied by the Licensor with the Licensed Material:

i. identification of the creator(s) of the Licensed Material and any others designated to receive attribution, in any reasonable manner requested by the Licensor (including by pseudonym if designated);

ii. a copyright notice;

iii. a notice that refers to this Public License;

iv. a notice that refers to the disclaimer of warranties;

v. a URI or hyperlink to the Licensed Material to the extent reasonably practicable;

b. indicate if You modified the Licensed Material and retain an indication of any previous modifications; and

c. indicate the Licensed Material is licensed under this Public License, and include the text of, or the URI or hyperlink to, this Public License.

2. You may satisfy the conditions in Section 3(a)(1) in any reasonable manner based on the medium, means, and context in which You Share the Licensed Material. For example, it may be reasonable to satisfy the conditions by providing a URI or hyperlink to a resource that includes the required information.

3. If requested by the Licensor, You must remove any of the information required by Section 3(a)(1)(A) to the extent reasonably practicable.

4. If You Share Adapted Material You produce, the Adapter's License You apply must not prevent recipients of the Adapted Material from complying with this Public License.

Section 4 -- Sui Generis Database Rights.

Where the Licensed Rights include Sui Generis Database Rights that apply to Your use of the Licensed Material:

a. for the avoidance of doubt, Section 2(a)(1) grants You the right to extract, reuse, reproduce, and Share all or a substantial portion of the contents of the database for NonCommercial purposes only;

b. if You include all or a substantial portion of the database contents in a database in which You have Sui Generis Database Rights, then the database in which You have Sui Generis Database Rights (but not its individual contents) is Adapted Material; and

c. You must comply with the conditions in Section 3(a) if You Share all or a substantial portion of the contents of the database.

For the avoidance of doubt, this Section 4 supplements and does not replace Your obligations under this Public License where the Licensed Rights include other Copyright and Similar Rights.

Section 5 -- Disclaimer of Warranties and Limitation of Liability.

a. UNLESS OTHERWISE SEPARATELY UNDERTAKEN BY THE LICENSOR, TO THE EXTENT POSSIBLE, THE LICENSOR OFFERS THE LICENSED MATERIAL AS-IS AND AS-AVAILABLE, AND MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND CONCERNING THE LICENSED MATERIAL, WHETHER EXPRESS, IMPLIED, STATUTORY, OR OTHER. THIS INCLUDES, WITHOUT LIMITATION, WARRANTIES OF TITLE, MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NON-INFRINGEMENT, ABSENCE OF LATENT OR OTHER DEFECTS, ACCURACY, OR THE PRESENCE OR ABSENCE OF ERRORS, WHETHER OR NOT KNOWN OR DISCOVERABLE. WHERE DISCLAIMERS OF WARRANTIES ARE NOT ALLOWED IN FULL OR IN PART, THIS DISCLAIMER MAY NOT APPLY TO YOU.

b. TO THE EXTENT POSSIBLE, IN NO EVENT WILL THE LICENSOR BE LIABLE TO YOU ON ANY LEGAL THEORY (INCLUDING, WITHOUT LIMITATION, NEGLIGENCE) OR OTHERWISE FOR ANY DIRECT, SPECIAL, INDIRECT, INCIDENTAL, CONSEQUENTIAL, PUNITIVE, EXEMPLARY, OR OTHER LOSSES, COSTS, EXPENSES, OR DAMAGES ARISING OUT OF THIS PUBLIC LICENSE OR USE OF THE LICENSED MATERIAL, EVEN IF THE LICENSOR HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH LOSSES, COSTS, EXPENSES, OR DAMAGES. WHERE A LIMITATION OF LIABILITY IS NOT ALLOWED IN FULL OR IN PART, THIS LIMITATION MAY NOT APPLY TO YOU.

c. The disclaimer of warranties and limitation of liability provided above shall be interpreted in a manner that, to the extent possible, most closely approximates an absolute disclaimer and waiver of all liability.

Section 6 -- Term and Termination.

a. This Public License applies for the term of the Copyright and Similar Rights licensed here. However, if You fail to comply with this Public License, then Your rights under this Public License terminate automatically.

b. Where Your right to use the Licensed Material has terminated under Section 6(a), it reinstates:

1. automatically as of the date the violation is cured, provided it is cured within 30 days of Your discovery of the violation; or

2. upon express reinstatement by the Licensor.

For the avoidance of doubt, this Section 6(b) does not affect any right the Licensor may have to seek remedies for Your violations of this Public License.

c. For the avoidance of doubt, the Licensor may also offer the Licensed Material under separate terms or conditions or stop distributing the Licensed Material at any time; however, doing so will not terminate this Public License.

d. Sections 1, 5, 6, 7, and 8 survive termination of this Public License.

Section 7 -- Other Terms and Conditions.

a. The Licensor shall not be bound by any additional or different terms or conditions communicated by You unless expressly agreed.

b. Any arrangements, understandings, or agreements regarding the Licensed Material not stated herein are separate from and independent of the terms and conditions of this Public License.

Section 8 -- Interpretation.

a. For the avoidance of doubt, this Public License does not, and shall not be interpreted to, reduce, limit, restrict, or impose conditions on any use of the Licensed Material that could lawfully be made without permission under this Public License.

b. To the extent possible, if any provision of this Public License is deemed unenforceable, it shall be automatically reformed to the minimum extent necessary to make it enforceable. If the provision cannot be reformed, it shall be severed from this Public License without affecting the enforceability of the remaining terms and conditions.

c. No term or condition of this Public License will be waived and no failure to comply consented to unless expressly agreed to by the Licensor.

d. Nothing in this Public License constitutes or may be interpreted as a limitation upon, or waiver of, any privileges and immunities that apply to the Licensor or You, including from the legal processes of any jurisdiction or authority.

Creative Commons is not a party to its public licenses. Notwithstanding, Creative Commons may elect to apply one of its public licenses to material it publishes and in those instances will be considered the “Licensor.” The text of the Creative Commons public licenses is dedicated to the public domain under the CC0 Public Domain Dedication. Except for the limited purpose of indicating that material is shared under a Creative Commons public license or as otherwise permitted by the Creative Commons policies published at creativecommons.org/policies, Creative Commons does not authorize the use of the trademark "Creative Commons" or any other trademark or logo of Creative Commons without its prior written consent including, without limitation, in connection with any unauthorized modifications to any of its public licenses or any other arrangements, understandings, or agreements concerning use of licensed material. For the avoidance of doubt, this paragraph does not form part of the public licenses.

Creative Commons may be contacted at creativecommons.org.