Healing of acute anterior cruciate ligament rupture on MRI and outcomes following non-surgical management with the Cross Bracing Protocol.

OBJECTIVE: Investigate MRI evidence of anterior cruciate ligament (ACL) healing, patient-reported outcomes and knee laxity in patients with acute ACL rupture managed non-surgically with the Cross Bracing Protocol (CBP). METHODS: Eighty consecutive patients within 4 weeks of ACL rupture were managed with CBP (knee immobilisation at 90° flexion in brace for 4 weeks, followed by progressive increases in range-of-motion until brace removal at 12 weeks, and physiotherapist-supervised goal-oriented rehabilitation). MRIs (3 months and 6 months) were graded using the ACL OsteoArthritis Score (ACLOAS) by three radiologists. Mann-Whitney U tests compared Lysholm Scale and ACL quality of life (ACLQOL) scores evaluated at median (IQR) of 12 months (7-16 months) post-injury, and χ2 tests compared knee laxity (3-month Lachman's test and 6-month Pivot-shift test), and return-to-sport at 12 months between groups (ACLOAS grades 0-1 (continuous±thickened ligament and/or high intraligamentous signal) versus ACLOAS grades 2-3 (continuous but thinned/elongated or complete discontinuity)). RESULTS: Participants were aged 26±10 years at injury, 39% were female, 49% had concomitant meniscal injury. At 3 months, 90% (n=72) had evidence of ACL healing (ACLOAS grade 1: 50%; grade 2: 40%; grade 3: 10%). Participants with ACLOAS grade 1 reported better Lysholm Scale (median (IQR): 98 (94-100) vs 94 (85-100)) and ACLQOL (89 (76-96) vs 70 (64-82)) scores, compared with ACLOAS grades 2-3. More participants with ACLOAS grade 1 had normal 3-month knee laxity (100% vs 40%) and returned to pre-injury sport (92% vs 64%), compared with participants with an ACLOAS grades 2-3. Eleven patients (14%) re-injured their ACL. CONCLUSION: After management of acute ACL rupture with the CBP, 90% of patients had evidence of healing on 3-month MRI (continuity of the ACL). More ACL healing on 3-month MRI was associated with better outcomes. Longer-term follow-up and clinical trials are needed to inform clinical practice.

Sagittal patellar flexion angle measurement determines greater incidence of patella alta in patellar tendinopathy patients.

PURPOSE: The objective of this study was to compare patellar height and patella alta between a control cohort and patients with patellar tendinopathy by the sagittal patellar flexion angle (SPFA) measurement. METHODS: Magnetic resonance imaging (MRI) scans of the knee were obtained from a sports imaging facility and screened to select patients with anterior knee pain. This symptomatic group was divided into two patient cohorts: those with and without MRI features of patellar tendinopathy. Lateral knee radiographs were reviewed and SPFA, knee flexion angle and Insall-Salvati ratio (IS) were measured from the radiographs by two independent reviewers. RESULTS: A total of 99 patients consisting of 48 patellar tendinopathy patients and 51 control patients were included. There was a significantly higher mean patellar height (p = 0.002, d = 0.639) and a greater patella alta incidence in the patellar tendinopathy cohort (25.0%) compared to the controls (3.9%) (p = 0.022, d = 0.312). Insall-Salvati ratio measurements showed no difference in patella alta incidence between tendinopathy and control cohorts. There was excellent inter- and intra-observer reliability of SPFA measurements (ICC 0.99). CONCLUSION: This is the first study to demonstrate a greater incidence of patella alta in patellar tendinopathy patients compared to controls. A greater patella alta incidence amongst patellar tendinopathy patients as defined by SPFA was found to be clinically relevant, as it suggests these patients may comprise the recalcitrant patient subgroup who do not improve with current surgical intervention and may therefore benefit from a biomechanical surgical solution. LEVEL OF EVIDENCE: III.

Moment arm function dictates patella sagittal height anatomy: Rabbit epiphysiodesis model alters limb length ratios and subsequent patellofemoral anatomical development.

Patellofemoral anatomical dysplasia is associated with patellofemoral instability and pain. The closure of the knee physis occurs at the same age as the peak incidence of patellofemoral dislocation. This study determined the effect on the patellofemoral anatomical development in a rabbit epiphysiodesis model. Twenty-four skeletally immature New Zealand White rabbits were divided into three groups (a) distal femur epiphysiodesis (FE) (b) proximal tibia epiphysiodesis (TE) (c) control; no epiphysiodesis (C) performed at 6 weeks of age. The primary endpoint was shape analysis using three-dimensional reconstructions of micro-computed tomographys (CTs) performed at 30 weeks of age. The limb length ratios (femur:tibia) were significantly different for both FE (mean 0.72, SD 0.0381, P < .001) and TE (mean 0.91, SD 0.0383, P < .001) treatment groups compared to control (mean 0.81, SD 0.0073). Patella height, as measured from the most distal point of the patella to the tibial joint surface (modified Caton-Deschamps measurement), was lower (baja) in the FE and higher (alta) for the TE, compared with the control group. Our findings suggest femoral and tibial shortening can influence the development of the patellofemoral joint, which may be dictated by moment arm function and is potentially responsible for the etiology of patella alta. Future studies are warranted to explore this association further with the view for the development of treatment options for patella alta in human patients.

Distalising tibial tubercle osteotomy decreases patellar tendon force - A treatment rationale for recalcitrant patellar tendinopathy.

BACKGROUND: Patellar tendinopathy is an overuse condition affecting athletes, often with a high morbidity if left untreated. High-level evidence fails to support the use of surgery. A tibial tubercle osteotomy (TTO) has been suggested as a surgical option to improve patient outcomes. Our aim was to explore whether a distalising TTO will alter the patellar tendon to quadriceps tendon force ratio and the sagittal patellar tilt. METHODS: Six cadaver limbs were placed in a custom jig with a mechanical testing machine applying cyclical loads of 200-500 N to the quadriceps tendon. The knee was fixed at 0, 15, 30, 45, 60, 75 and 90° of flexion and a buckle transducer recorded the resultant patellar tendon force. Testing was performed with the native tibial tubercle position and with the tubercle distalised by 11 mm. Testing was also performed with the tubercle anteriorised by 10 mm at both of these tubercle positions, a total of four different testing positions. RESULTS: There was a significant decrease in the patellar tendon to quadriceps tendon force ratio from 30-60° of knee flexion. There was a significant increase in the sagittal patellar tilt at 30° of knee flexion with distalisation. CONCLUSION: This biomechanical study shows that the patellar tendon to quadriceps tendon force ratio can be altered with a distalising tibial tubercle osteotomy. A tibial tubercle osteotomy may be a biomechanical treatment option for recalcitrant patellar tendinopathy by decreasing the load through the patellar tendon, allowing the athlete to maintain higher training volumes and loads.

Patella tendinopathy Zoobiquity - What can we learn from dogs?

BACKGROUND: Patella tendinopathy is an overuse condition. Pathogenesis and identification of intrinsic risk factors have largely eluded the orthopaedic world. The cranial cruciate ligament (CrCL) in dogs is the equivalent to the human anterior cruciate ligament (ACL). We report the effect of two canine proximal tibial osteotomy procedures in the veterinary literature on patella tendon moment arm and describe the biomechanical rationale for a tibial tubercle osteotomy for treatment of patella tendinopathy in the human. METHODS: A literature review of studies reporting clinical complications of TTA and TPLO to form an observational animal cohort study in dogs. RESULTS: The veterinary literature reports an overall clinical complication rate of up to 61% for TTA and up to 50% for TPLO respectively. Complications associated with the extensor mechanism of the knee are <1% for TTA compared to 1.9-19% for TPLO. Radiographic thickening of the patella tendon and tendinopathy is seen in one to 80% of TPLO cases. The TPLO decreases the moment arm of the extensor mechanism meaning increased force is required in the patella tendon to achieve the same torque when compared to the TTA which increases the efficiency of the extensor mechanism. This difference may account, in part, for the post-operative complications reported to the patella and patella tendon following TPLO. CONCLUSION: This observational animal cohort study demonstrates a biomechanical rationale for investigating diagnostic and potential treatment options, including a tibial tubercle osteotomy, for patella tendinopathy in humans based on this principle.

Treatment of patella tendinopathy by distalising tibial tubercle osteotomy.

Patella tendinopathy condition is often resistant to conservative treatment. We report a case of patella tendinopathy treated by distalisation of the tibial tubercle with excellent long-term result.

The effect of surgery on patellar tendinopathy: Novel use of MRI questions the exploitability of the rat collagenase model to humans.

BACKGROUND: patellar tendinopathy is an overuse condition most commonly affecting jumping athletes. Surgery is reserved for refractory cases; however, it lacks high level clinical evidence and basic science to support its use. The purpose of this study was to determine the biomechanical and histological response of surgical excision on patellar tendinopathy in the rat collagenase tendinopathy model and correlate MRI findings. METHODS: Forty-eight Long Evans rats were divided into three groups: i) no patellar tendinopathy with surgical excision, ii) patella tendinopathy with surgical excision, and iii) patellar tendinopathy with no surgical excision. Endpoints included histology, mechanical testing, and MRI pre- and post-surgical intervention at one and four weeks. RESULTS: No difference in failure load or histological grading was seen between the groups at all time points. MRIs showed initial loss of tendon continuity followed by complete healing with elongated and thickened tendons in all groups. CONCLUSIONS: While other research has reported immunohistochemistry and histology of collagenase-induced tendinopathy may be correlated with human pathogenesis, the novel MRI findings from our study suggest that the rat collagenase tendinopathy surgical model may be limited when extrapolating to humans. Further work is needed to determine if any correlation exists between the dosing, location, and animal effect of the collagenase injection model with MRI findings. This is needed before any collagenase model can be used to determine the effect of surgery in the pathogenic response to patella tendinopathy.

Biomechanics of the knee extensor mechanism and its relationship to patella tendinopathy: A review.

The term jumpers knee for patella tendinitis, as coined by Dr. Martin Blazina, is now commonly referred to as tendinopathy. He believed it was associated with patella alta. Since then multiple studies have failed to reliably show an association between patella tendinopathy and associated intrinsic risk factors. There is, unfortunately, a well-established doctrine that the extensor mechanism is simply a pulley. The goal of the review is to examine the biomechanics of the extensor mechanism and apply this to studies investigating intrinsic risk factors for patella tendinopathy. A better understanding of the biomechanics of the extensor mechanism may stimulate the discovery of intrinsic risk factors for developing patella tendinopathy, and subsequent surgical options to address them. Clinical significance: The aim of this review is to direct future research into biomechanical risk factors for developing patella tendinopathy and subsequently, possible treatments. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:3105-3112, 2018.

Semimembranosus tenosynovitis: Diagnosis and management of a commonly missed cause of posteromedial knee pain.

BACKGROUND: In orthopedic and sports medicine literature there is minimal information regarding accurate diagnosis and the treatment options for tenosynovitis of the distal semimembranosus tendon. After reviewing the literature, the authors question both the etiology and treatment of this condition. Previous descriptions have associated the condition primarily with the endurance athlete but we have noted multiple cases in which this is a condition common to the 'sprinter' as well. There has been very little mention of this condition in recent literature but the most recent complete description of operative treatment for this condition recommends both tendon transfer and concomitant arthroscopy. We propose this condition is akin to De Quervain's tenosynovitis of the knee, with sensitive and specific signs on physical examination. METHODS: We describe a case series of six cases (five patients), that underwent open surgical release for semimembranosus tenosynovitis. The anatomy and the treatment options for the condition are also discussed. RESULTS: At a follow-up period of 18-64months, all cases showed improvement in the Tegner activity score following surgical release. CONCLUSION: Diagnostic confusion can be decreased with more modern diagnostic imaging modalities than those described in the literature. The authors outline an alternative operative approach significantly decreasing surgical complexity and therefore post-operative morbidity. What is known about this subject: This is a rare condition and the surgical treatment is seldom performed. What this study adds to existing knowledge: We describe the technique for surgical decompression and reveal positive results at medium term follow-up.

Ganglion cysts of the anterior cruciate ligament: a series of 15 cases.

PURPOSE: To increase awareness of the presence of ganglion cysts of the anterior cruciate ligament and to consider this diagnosis in any knee that has lost range of motion (ROM) in the absence of osteoarthritis. TYPE OF STUDY: Case series. METHODS: We present a series of 15 cases recorded over a period of 5 years illustrating the clinical presentation and additional pathology seen at arthroscopy. International Knee Documentation Committee scores were calculated at the recent follow-up to establish outcome of the surgery. RESULTS: The cysts occurred predominantly in men with the most common presenting complaint being decreased ROM and pain. Overall, results were excellent with no recurrence of symptoms at a mean 36-month follow-up, but outcome does appear to be associated with other pathology present. ROM was improved with arthroscopic excision of the cyst in all cases that were impaired. CONCLUSIONS: Although rare, ganglion cysts related to the cruciate ligaments of the knee should be considered in the differential diagnosis of a painful knee especially when associated with a decreased ROM and no evidence of osteoarthritis on radiographs. Other pathology can often be present, which may affect the overall outcome, but arthroscopic debridement of the ganglion cyst should be considered the treatment of choice in order to reliably restore active ROM. LEVEL OF EVIDENCE: Level IV, Case Series.

Does anterior cruciate ligament reconstruction lead to degenerative disease?: Thirteen-year results after bone-patellar tendon-bone autograft.

BACKGROUND: Reporting of long-term outcome of anterior cruciate ligament (ACL) reconstruction with the patellar tendon (bone-patellar tendon-bone [BTB]) autograft is limited. There are concerns that degenerative joint disease is common in the long term, which may be associated with the procedure itself. HYPOTHESES: (1) ACL reconstruction with BTB provides good long-term outcome. (2) There are additional factors to surgical reconstruction that can be associated with the development of degenerative disease. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Of 161 patients, 114 were eligible. Patient-centered outcome was by Lysholm and subjective International Knee Documentation Committee (IKDC) score; objective outcome measures were clinical examination and IKDC radiological grade. RESULTS: Mean average follow-up was 13 years. The IKDC radiological grades in the worst compartment were A = 15%, B = 51%, C = 19%, and D = 14% (n = 83). There was a significant difference between the injured versus contralateral uninjured knee (n = 42, P = .003). In a subgroup with no meniscal or chondral injury the IKDC grades were A = 38%, B = 55%, C = 7%, and D = 0% (n = 29). The mean subjective scores were 89 ± 11 (Lysholm) and 83 ± 15 (IKDC) (n = 114). Poor IKDC subjective outcome was associated with chondral injury (P = .001), previous surgery (P = .022), return to sport (P = .013), and poor radiological grade in the ipsilateral medial compartment (P = .004). A poor IKDC radiological grade was associated with chondral injury (P = .002), meniscal injury (P = .010) and meniscectomy (P = .012), an IKDC subjective score of <85 (P = .01), and poor radiological grade in the contralateral medial compartment (P = .041). CONCLUSION: At 13 years, BTB ACL reconstruction provides a good outcome. Chondral and meniscal damage at surgery were associated with a poor radiological outcome, indicating that injuries sustained during ACL rupture may be the main predictors of degenerative bone disease.

The use of an articulating spacer in the management of infected total knee arthroplasties.

Eleven infected total knee arthroplasties underwent revision using an articulating spacer comprising a total condylar component and meniscal polyethylene insert cemented in place using antibiotic-loaded cement. Only 1 case required subsequent rerevision for infection, 2 were revised for pain, 6 remain in situ, and 2 patients have died with their spacers in situ. Average Knee Society clinical rating for the spacers left implanted is 167 at an average of 65 months. This articulating spacer appears not to require mandatory second-stage surgery, although should this prove necessary, then it is relatively straightforward to perform.

Surgical reconstruction of severe patellofemoral maltracking.

Dysfunction of the patellofemoral mechanism presents in many ways. Results from different realignment procedures show great variability in patient outcome. A surgical technique is presented that attempts to correct all the abnormalities of patellofemoral maltracking. The procedure consists of a lateral release, a vastus medialis (obliquus) tendon advancement, and a tibial tubercle transfer. Along with being moved medially, the tubercle also is moved distally to correct patella alta and elevated anteriorly to reduce patellofemoral joint reaction forces. One hundred seven knees in 84 patients were reviewed. Fifty-five percent of patients had frank dislocation. The remaining patients had anterior knee pain and had abnormal patella tracking on examination. The mean followup was 5.6 years. Seventy-nine percent of patients had a good to excellent functional outcome and 84% of patients stated they would have the operation again. Two patients with marked generalized ligamentous laxity had recurrent dislocation of the patella.