Medial patellar ligament reconstruction in combination with derotational distal femoral osteotomy for treating recurrent patellar dislocation in the presence of increased femoral anteversion: a systematic review.

BACKGROUND: Medial patellar ligament reconstruction (MPFL-R) in combination with derotational distal femoral osteotomy (DDFO) for treating recurrent patellar dislocation (RPD) in the presence of increased femoral anteversion is one of the most commonly used surgical techniques in the current clinical practice. However, there are limited studies on the clinical outcomes of MPFL-R in combination with DDFO to treat RPD in the presence of increased femoral anteversion. PURPOSE: To study the role of MPFL-R in combination with DDFO in the treatment of RPD in the presence of increased femoral anteversion. METHODS: A systematic review was performed according to the PRISMA guidelines by searching the Medline, Embase, Web of Science, and Cochrane Library databases through June 1, 2023. Studies of patients who received MPFL-R in combination with DDFO after presenting with RPD and increased femoral anteversion were included. Methodological quality was assessed using the MINORS (Methodological Index for Nonrandomized Studies) score. Each study's basic characteristics, including characteristic information, radiological parameters, surgical techniques, patient-reported outcomes, and complications, were recorded and analyzed. RESULTS: A total of 6 studies with 231 patients (236 knees) were included. Sample sizes ranged from 12 to 162 patients, and the majority of the patients were female (range, 67-100%). The mean age and follow-up ranges were 18 to 24 years and 16 to 49 months, respectively. The mean femoral anteversion decreased significantly from 34° preoperatively to 12° postoperatively. In studies reporting preoperative and postoperative outcomes, significant improvements were found in the Lysholm score, Kujala score, International Knee Documentation Committee score, and visual analog scale for pain. Postoperative complications were reported in all studies, with an overall reported complication rate of 4.7%, but no redislocations occurred during the follow-up period. CONCLUSION: For RPD with increased femoral anteversion, MPFL-R in combination with DDFO leads to a good clinical outcome and a low redislocation rate. However, there was no consensus among researchers on the indications for MPFL-R combined with DDFO in the treatment of RPD.

Acute Patellar Tendon Ruptures: An Update on Management.

Patellar tendon ruptures can be debilitating injuries. When incomplete, partial tears can be managed nonsurgically with immobilization and progressive rehabilitation. Although complete ruptures remain a relatively uncommon injury, they portend a high level of morbidity. Ruptures typically result from an acute mechanical overload to the extensor mechanism, such as with forced quadriceps contraction and knee flexion. However, chronically degenerated tendons are also predisposed to failure from low-energy injuries. Diagnosis can often be made clinically with recognition of a palpable defect to the tendon, localized patellar tendon tenderness, and inability to actively extend the knee. Diagnosis and surgical planning can be established with radiograph, ultrasonography, or magnetic resonance imaging. Surgical repair is the mainstay of treatment, and there have been many recent advances in repair technique, optimal reconstruction strategies, and supplemental fixation. Time to surgery for complete tears remains the most important prognosticator for success. Direct primary repair can be completed with transosseous tunnels, suture anchor repair, or end-to-end repair. Tendon reconstruction can be achieved with or without mechanical or biologic augments. Rehabilitation programs vary in specifics, but return to sport can be expected by 6 months postoperatively.

Reconstruction of medial meniscus posterior portion deficiency in pigs with an autologous patellar tendon graft: an experimental study.

OBJECTIVE: This study was performed to investigate the effectiveness of two surgical procedures, autologous patellar tendon graft reconstruction and trans-tibial plateau pull-out repair, using a pig model. The primary focus was to assess the repair capability of medial meniscus posterior portion (MMPP) deficiency, the overall structural integrity of the meniscus, and protection of the femoral and tibial cartilage between the two surgical groups. The overall aim was to provide experimental guidelines for clinical research using these findings. METHODS: Twelve pigs were selected to establish a model of injury to the MMPP 10 mm from the insertion point of the tibial plateau. They were randomly divided into three groups of four animals each: reconstruction (autologous tendon graft reconstruction of the MMPP), pull-out repair (suture repair of the MMPP via a trans-tibial plateau bone tunnel), and control (use of a normal medial meniscus as the negative control). The animals were euthanized 12 weeks postoperatively for evaluation of the meniscus, assessment of tendon bone healing, and gross observation of knee joint cartilage. The tibial and femoral cartilage injuries were evaluated using the International Society for Cartilage Repair (ICRS) grade and Mankin score. Histological and immunohistochemical staining was conducted on the meniscus-tendon junction area, primary meniscus, and tendons. The Ishida score was used to evaluate the regenerated meniscus in the reconstruction group. Magnetic resonance imaging (MRI) was used to evaluate meniscal healing. RESULTS: All 12 pigs recovered well after surgery; all incisions healed without infection, and no obvious complications occurred. Gross observation revealed superior results in the reconstruction and pull-out repair groups compared with the control group. In the tibial cartilage, the reconstruction group had ICRS grade I injury whereas the pull-out repair and control groups had ICRS grade II and III injury, respectively. The Mankin score was significantly different between the reconstruction and control groups; histological staining showed that the structure of the regenerated meniscus in the reconstruction group was similar to that of the original meniscus. Immunohistochemical staining showed that the degree of type I and II collagen staining was similar between the regenerated meniscus and the original meniscus in the reconstruction group. The Ishida score was not significantly different between the regenerated meniscus and the normal primary meniscus in the reconstruction group. MRI showed that the MMPP in the reconstruction and pull-out repair groups had fully healed, whereas that in the control group had not healed. CONCLUSION: Autologous patellar tendon graft reconstruction of the MMPP can generate a fibrocartilage-like regenerative meniscus. Both reconstruction and pull-out repair can preserve the structural integrity of the meniscus, promote healing of the MMPP, delay meniscal degeneration, and protect the knee cartilage.

Comparison of Graft Type and Fixation Method in Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-analysis Based on Randomized Control Studies.

BACKGROUND: The anterior cruciate ligament (ACL) is the most commonly injured ligament in the knee. ACL reconstruction (ACLR) proves the standard for treating this injury. However, graft choice and method of fixation remain a heavily debated topic. This study investigates the following: bone-patellar tendon-bone (BPTB) vs. hamstring tendon (HT) autograft, single-bundle vs. double-bundle hamstring graft, and metal vs. bioabsorbable screws in ACLR. METHODS: A systematic review was performed on PubMed and Google Scholar according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Data were collected on patient demographics, complications, and functionality scores including International Knee Documentation Committee (IKDC) and Lysholm scores. A systematic review and meta-analysis were conducted with Review Manager. Outcome measurements were determined using forest plots with significant differences considered p < 0.05. RESULTS: Twenty-five studies were included, accounting for 2,170 patients. No statistically significant difference was appreciated when comparing BPTB to hamstring autografts. Patients who received a double bundle HT autograft exhibited significantly superior outcomes in terms of revision (p = 0.05), failure (p = 0.002), normal pivot shift tests (p = 0.04), and normal IKDC (p = 0.008). When comparing screw types, bioabsorbable screws had a greater Lysholm score (p = 0.01) and lower failure rates for copolymer screws (p = 0.03). CONCLUSION: Overall, the data collected suggested that BPTB and HT autografts display similar postoperative results. However, if an HT autograft is used, the data suggest a double-bundle graft improves both functionality and decreases the possible complications. Finally, bioabsorbable screws prove superior to metal screws when looking at both functionality and failure rates. Further research into the superior graft type is still needed. LEVEL OF EVIDENCE: Level II. See Instructions for Authors for a complete description of levels of evidence.

Satisfactory 5-year functional outcomes following primary ACL reconstructions from the UK National Ligament Registry.

PURPOSE: The aim of this study was to describe the 10-year findings from the UK National Ligament Registry (NLR). METHODS: A retrospective review was performed for prospectively collected data on the NLR between January 2013 and December 2022. All patients who underwent primary ACL reconstruction (ACLR) on the registry were included. Surgical characteristics were analysed, including surgeon grade and case volume, concomitant knee procedures, venous thromboembolic prophylaxis, graft characteristics, femoral and tibial tunnel drilling, and fixation methods. Clinical outcomes were collected preoperatively and at 6 months, 1 year, 2 years and 5 years following the index procedure. RESULTS: During the study period, 17,492 unilateral ACLR procedures were recorded. Autograft was used in 98%, most commonly a combined semitendinosus and gracilis graft (77%) or patella tendon graft (31%). Allograft was used in only 1% of the patients. In 52% of cases, ACLR was associated with an additional procedure, with isolated medial meniscal surgery being the most common (21%). Femoral tunnel drilling was mostly performed through an anteromedial portal (73%) and tibial tunnel drilling using an outside-in technique (92%). The most common method of femoral graft fixation was with an Endobutton fixed loop suspensory device (77%), while interference screws predominated for tibial tunnel fixation (86%). Patients who underwent ACLR surgery showed significant improvement in their functional outcome scores at six months, 1 year, 2 years and 5 years postoperatively. CONCLUSION: Data from the NLR shows a detailed description of the current trends and evolution of ACLR in the United Kingdom over the last 10 years. Satisfactory functional outcomes were observed 5 years postoperatively. This study provides useful information on the prevalence of ACL-associated injuries and current surgical techniques with the aim of improving the quality of clinical care and patients' outcomes. Moreover, it provides surgeons with a benchmark against which to compare current practices and functional outcomes following ACLR across the United Kingdom. LEVEL OF EVIDENCE: Level III.

Plastic and elastic biomechanical properties of anterior cruciate ligament autografts.

BACKGROUND: Anterior cruciate ligament (ACL) rupture is a common orthopedic injury, occurring in roughly 68.6 per 100,000 persons annually, with the primary treatment option being ACL reconstruction. However, debate remains about the appropriate graft type for restoring the native biomechanical properties of the knee. Furthermore, plastic graft elongation may promote increased knee laxity and instability without rupture. This study aims to investigate the plastic properties of common ACL-R graft options. METHODS: Patellar tendon (PT), hamstring tendon (HT), and quadriceps tendon (QT) grafts were harvested from 11 cadaveric knees (6 male and 5 female) with a mean age of 71(range 55-81). All grafts were mechanically tested under uniaxial tension until failure to determine each graft's elastic and plastic biomechanical properties. RESULTS: Mechanically, the QT graft was the weakest, exhibiting the lowest failure force and the lowest failure stress (QT < HT, p = 0.032). The PT was the stiffest of the grafts, having a significantly higher stiffness (PT > QT, p = 0.0002) and Young's modulus (PT > QT, p = 0.001; PT > HT, p = 0.041). The HT graft had the highest plastic elongation at 4.01 ± 1.32 mm (HT > PT, p = 0.002). The post-yield behavior of the HT tendon shows increased energy storage capabilities with the highest plastic energy storage (HT > QT, p = 0.012) and the highest toughness (HT > QT, p = 0.032). CONCLUSION: Our study agrees with prior studies indicating that the failure load of all grafts is above the requirements for everyday activities. However, grafts may be susceptible to yielding before failure during daily activities. This may result in the eventual loss of functionality for the neo-ACL, resulting in increased knee laxity and instability.

Increased risk for early revision with quadriceps graft compared with patellar tendon graft in primary ACL reconstructions.

PURPOSE: Bone patella-tendon bone (BPTB) and hamstring tendon (HT) autografts are the most used grafts in primary anterior cruciate ligament (ACL) reconstructions (ACLR) in Norway. Quadriceps tendon (QT) autograft has gained more popularity during the past years. The purpose of this study is to compare revision rates and patient-reported outcomes of primary QT with BPTB and HT autograft ACL reconstructions in Norway at 2-year follow-up. It was hypothesized that there would be no difference in 2-year revision rates between all three autografts. METHODS: Data included primary ACLR without concomitant ligament surgeries, registered in the Norwegian Knee Ligament Register from 2004 through 2021. Revision rates at 2 years were calculated using Kaplan-Meier analysis. Hazard ratios (HR) for revision were estimated using multivariable Cox regression analysis with revision within 2 years as endpoint. Mean change in patient-reported outcome was recorded preoperatively and at 2 years through the Knee Injury and Osteoarthritis Outcome Score (KOOS) subcategories 'Sport' and 'Quality of Life' was measured for patients that were not revised and analysed with multiple linear regression. RESULTS: A total of 24,790 primary ACLRs were identified, 10,924 with BPTB, 13,263 with HT and 603 with a QT graft. Patients in the QT group were younger (23.5 years), more of them were women (58.2%) and over 50% had surgery <3 months after injury. The QT group had the highest prevalence of meniscal injuries (61.9%). Revision estimates at 2-years were 3.6%, 2.5% and 1.2% for QT, HT and BPTB, respectively (p < 0.001). In a Cox regression analysis with QT as reference, BPTB had a lower risk of revision (HR 0.4, 95% Cl 0.2-0.7, p < 0.001). No significant difference was observed in the revision risk between QT and HT (HR 1.1, 95% Cl 0.7-1.8, n.s.). The two most common reported reasons for revision were: traumatic graft rupture and nontraumatic graft failure. There were no differences between the groups in change of KOOS in subcategories 'Sport' and 'Quality of Life' at 2-years follow-up. CONCLUSION: The 2-year risk of revision after ACLR with QT was higher than BPTB and similar to HT. No difference was found between the groups in patient-reported outcomes. This study provides valuable insights for both surgeons and patients when making decisions about the choice of autografts in primary ACL reconstructions. LEVEL OF EVIDENCE: Level II.

Risk of Revision and Reoperation After Quadriceps Tendon Autograft ACL Reconstruction Compared With Patellar Tendon and Hamstring Autografts in a US Cohort of 21,973 Patients.

BACKGROUND: The use of quadriceps tendon (QT) autografts has increased in the past 10 years. However, there remains a dearth of large studies examining the effects of graft selection on anterior cruciate ligament reconstruction (ACLR) that includes QT grafts. PURPOSE: To evaluate the risk of subsequent surgical outcomes, including revision and reoperation, for a large cohort of patients with primary ACLR according to autograft selection. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Data from a US health care system ACLR registry were used to conduct a cohort study. Primary isolated autograft ACLRs were identified (2012-2021). The exposure of interest was autograft type: QT, bone-patellar tendon-bone (BPTB), and hamstring tendon (HT). Multivariable Cox regression models were used to evaluate the risk of aseptic revision (defined as a subsequent surgery where removal and replacement of the original graft for noninfectious reasons was required) and risk of aseptic reoperation (defined as any subsequent surgery for noninfectious reasons where the graft was left intact) according to autograft selection. RESULTS: The study sample comprised 21,973 ACLRs performed by 290 surgeons at 53 hospitals. QT, BPTB, and HT autografts were used in 1103 (5.0%), 9519 (43.3%), and 11,351 (51.7%) ACLRs, respectively. In adjusted models, no significant differences were observed in revision risk (hazard ratio [HR], 1.06; 95% CI, 0.60-1.89; P = .837) or reoperation risk (HR, 1.00; 95% CI, 0.70-1.43; P = .993) within 4 years of follow-up when comparing QT ACLR with BPTB ACLR. Additionally, no differences in 4-year revision (HR, 0.62; 95% CI, 0.34-1.12; P = .111) or reoperation (HR, 1.24; 95% CI, 0.85-1.80; P = .262) risks were observed when comparing QT ACLR with HT ACLR. HT ACLRs were noted to have a higher risk of revision (HR, 1.52; 95% CI, 1.25-1.84; P < .001) compared with BPTB ACLRs but a lower risk of reoperation (HR, 0.86; 95% CI, 0.75-0.98; P = .024). CONCLUSION: In this large multicenter study using data from an ACLR registry, the authors found no difference in the risk of revision or reoperation when QT was compared with BPTB or HT autograft with the numbers available, but they did find a 1.5 times higher risk of revision when HT autograft was compared with BPTB autograft. Surgeons may use this information when choosing the appropriate graft for ACLR in their patients.

External validation of the Norwegian anterior cruciate ligament reconstruction revision prediction model using patients from the STABILITY 1 Trial.

PURPOSE: A machine learning-based anterior cruciate ligament (ACL) revision prediction model has been developed using Norwegian Knee Ligament Register (NKLR) data, but lacks external validation outside Scandinavia. This study aimed to assess the external validity of the NKLR model (https://swastvedt.shinyapps.io/calculator_rev/) using the STABILITY 1 randomized clinical trial (RCT) data set. The hypothesis was that model performance would be similar. METHODS: The NKLR Cox Lasso model was selected for external validation owing to its superior performance in the original study. STABILITY 1 patients with all five predictors required by the Cox Lasso model were included. The STABILITY 1 RCT was a prospective study which randomized patients to receive either a hamstring tendon autograft (HT) alone or HT plus a lateral extra-articular tenodesis (LET). Since all patients in the STABILITY 1 trial received HT ± LET, three configurations were tested: 1: all patients coded as HT, 2: HT + LET group coded as bone-patellar tendon-bone (BPTB) autograft, 3: HT + LET group coded as unknown/other graft choice. Model performance was assessed via concordance and calibration. RESULTS: In total, 591/618 (95.6%) STABILITY 1 patients were eligible for inclusion, with 39 undergoing revisions within 2 years (6.6%). Model performance was best when patients receiving HT + LET were coded as BPTB. Concordance was similar to the original NKLR prediction model for 1- and 2-year revision prediction (STABILITY: 0.71; NKLR: 0.68-0.69). Concordance 95% confidence interval (CI) ranged from 0.63 to 0.79. The model was well calibrated for 1-year prediction while the 2-year prediction demonstrated evidence of miscalibration. CONCLUSION: When patients in STABILITY 1 who received HT + LET were coded as BPTB in the NKLR prediction model, concordance was similar to the index study. However, due to a wide 95% CI, the true performance of the prediction model with this Canadian and European cohort is unclear and a larger data set is required to definitively determine the external validity. Further, better calibration for 1-year predictions aligns with general prediction modelling challenges over longer periods. While not a large enough sample size to elicit the true accuracy and external validity of the prediction model when applied to North American patients, this analysis provides more support for the notion that HT plus LET performs similarly to BPTB reconstruction. In addition, despite the wide confidence interval, this study suggests optimism regarding the accuracy of the model when applied outside of Scandinavia. LEVEL OF EVIDENCE: Level 3, cohort study.

Derotational distal femoral osteotomy improves subjective function and patellar tracking after medial patellofemoral ligament reconstruction in recurrent patellar dislocation patients with increased femoral anteversion: A systematic review and meta-analysis.

PURPOSE: The purpose of this study is to systematically review and quantitatively analyse the clinical outcomes of combined derotational distal femoral osteotomy (D-DFO) and medial patellofemoral ligament reconstruction (MPFL-R) in the treatment of recurrent patellar dislocation (RPD) with increased femoral anteversion angle (FAA). METHODS: This study was performed in line with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) and AMSTAR (Assessing the Methodological Quality Of Systematic Reviews) Guidelines. PubMed, Embase, Web of Science and Cochrane Library databases were searched to identify studies reporting clinical outcomes of combined D-DFO and MPFL-R in RPD patients with increased FAA. Data on patient-reported outcome measures, radiological parameters, patellar tracking as revealed by J-sign and complications were extracted based on the inclusion criteria. The Methodological Index for Non-Randomized Study score was used for quality assessment. Review Manager and R statistical software were used to perform the statistical analysis. RESULTS: Eleven studies with a total of 569 knees in 553 patients were included. Patients were predominantly female (79%). The weighted mean of FAA decreased from 33.6° to 13.0° (weighted mean difference = 20.59; p < 0.00001) after the combined procedure. Significant improvements (p < 0.00001) were identified in the Lysholm score (weighted mean: 55.5 vs. 80.4), International Knee Documentation Committee (IKDC) score (weighted mean: 52.8 vs. 78.6) and Kujala score (weighted mean: 54.5 vs. 80.6). The incidence of residual J-sign ranged from 14.3% to 38.3% with an overall pooled rate of 28.2% (95% confidence interval = 22.8%-33.6%). The overall redislocation rate was 1.1%. No patients experienced surgical site infection or bone nonunion. Two studies compared the clinical outcomes of MPFL-R with and without D-DFO. Compared with isolated MPFL-R, the combined procedure yielded a better Lysholm score (weighted mean: 84.9 vs. 79.3, p < 0.0001), IKDC score (weighted mean: 84.1 vs. 79.9, p = 0.001), Kujala score (weighted mean: 84.3 vs. 79.4, p < 0.0001) and a lower residual J-sign rate (26/97 [26.8%] vs. 44/105 [41.9%], p = 0.02), respectively. CONCLUSION: The combination of D-DFO and MPFL-R led to improved clinical outcomes and a low redislocation rate in patients with RPD and increased FAA. Additional D-DFO can achieve more favourable results in subjective function and patellar tracking than isolated MPFL-R in the setting of excessive FAA. LEVEL OF EVIDENCE: Level IV.

Patellar Tendon Reconstruction After Failed Primary Repair of Bilateral Ruptures: A Case Report.

CASE: A 29-year-old man sustained a bilateral acute patellar tendon rupture (PTR) while jumping on a trampoline. He was initially treated with bilateral transosseous patellar tendon repairs. Bilateral rerupture occurred during a fall 10 weeks after. He subsequently underwent staged bilateral patellar tendon reconstructions using an Achilles tendon allograft. At 3-year follow-up, he has maintained full range of motion and leg strength without rerupture or other complications. CONCLUSION: The use of Achilles tendon allograft in the presence of inadequate and poor-quality tendon tissue for reconstruction of the patellar tendon in the revision setting is a viable and effective treatment option.

Weaker Quadriceps Muscle Strength With a Quadriceps Tendon Graft Compared With a Patellar or Hamstring Tendon Graft at 7 Months After Anterior Cruciate Ligament Reconstruction.

BACKGROUND: Impaired quadriceps muscle strength after anterior cruciate ligament reconstruction (ACLR) is associated with worse clinical outcomes and a risk of reinjuries. Yet, we know little about quadriceps muscle strength in patients reconstructed with a quadriceps tendon (QT) graft, which is increasing in popularity worldwide. PURPOSE: To describe and compare isokinetic quadriceps strength in patients undergoing ACLR with a QT, hamstring tendon (HT), or bone-patellar tendon-bone (BPTB) autograft. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: We included patients with QT grafts (n = 104) and matched them to patients with HT (n = 104) and BPTB (n = 104) grafts based on age, sex, and associated meniscal surgery. Data were collected through clinical strength testing at a mean of 7 ± 1 months postoperatively. Isokinetic strength was measured at 90 deg/s, and quadriceps strength was expressed as the limb symmetry index (LSI) for peak torque, total work, torque at 30° of knee flexion, and time to peak torque. RESULTS: Patients with QT grafts had the most impaired isokinetic quadriceps strength, with the LSI ranging between 67.5% and 75.1%, followed by those with BPTB grafts (74.4%-81.5%) and HT grafts (84.0%-89.0%). Patients with QT grafts had a significantly lower LSI for all variables compared with patients with HT grafts (mean difference: peak torque: -17.4% [95% CI, -21.7 to -13.2], P < .001; total work: -15.9% [95% CI, -20.6 to -11.1], P < .001; torque at 30° of knee flexion: -8.8% [95% CI, -14.7 to -2.9], P = .001; time to peak torque: -17.7% [95% CI, -25.8 to -9.6], P < .001). Compared with patients with BPTB grafts, patients with QT grafts had a significantly lower LSI for all variables (mean difference: peak torque: -6.9% [95% CI, -11.2 to -2.7], P < .001; total work: -7.7% [95% CI, -12.4 to -2.9], P < .001; torque at 30° of knee flexion: -6.3% [95% CI, -12.2 to -0.5], P = .03; time to peak torque: -8.8% [95% CI, -16.9 to -0.7], P = .03). None of the graft groups reached a mean LSI of >90% for peak torque (QT: 67.5% [95% CI, 64.8-70.1]; HT: 84.9% [95% CI, 82.4-87.4]; BPTB: 74.4% [95% CI, 72.0-76.9]). CONCLUSION: At 7 months after ACLR, patients with QT grafts had significantly worse isokinetic quadriceps strength than patients with HT and BPTB grafts. None of the 3 graft groups reached a mean LSI of >90% in quadriceps strength.

Rehabilitation exercise program after surgical treatment of patellar tendon rupture: A case report.

OBJECTIVE: This case report describes in detail a rehabilitation and exercise program following surgical treatment of patellar tendon rupture and offers postoperative therapeutic goals and recommendations, with the aim of expediting the resumption of activities of daily living and sports participation following the surgical procedure. In addition, this report analyzes the cause of the patellar tendon rupture in this case. DESIGN: Case report. PARTICIPANTS: The patient, a 25-year-old male recreational athlete (height: 184 cm; weight: 80 kg; right-hand dominant), experienced a complete rupture of the patellar tendon upon landing on the left lower extremity during an unopposed dribble turn. REHABILITATION EXERCISE PROGRAM: A well-structured rehabilitation program was implemented. Passive knee flexion range of motion (ROM) exceeded 90° at week 5 and was fully recovered at week 16. A second surgery was performed at week 19 to remove the decompression wires, and the patient progressively resumed basic physical and specialized training at 7 months post-surgery. MAIN OUTCOME MEASURES: Morphometric and functional tests were performed to measure the effectiveness of rehabilitation throughout the postoperative process. CONCLUSIONS: Early surgical repair and an immediate postoperative rehabilitation program have a positive impact on knee ROM, function, and muscle strength. The causes of the patellar tendon rupture in this patient included long-standing uncontrolled patellar tendinopathy, impaired mobility of the ankle and hip joints, poor landing technique, and muscle strength imbalances.

Biomechanical Comparison of Four- versus Six-Strand Transosseous Suture Repair for Patellar Tendon Rupture.

BACKGROUND: Surgical repair is indicated for patellar tendon ruptures that result in loss of knee extensor mechanism function. However, biomechanical studies report conflicting results when comparing transosseous suture versus suture anchor repair techniques. This discrepancy may be due to inconsistencies in experimental design as these studies use various numbers of suture strands. Therefore, the main objective of this study is to compare the ultimate load of four- versus six-strand transosseous suture repair. Secondary objectives are to compare gap formation after cyclical loading and mode of failure. METHODS: Six pairs of fresh-frozen cadaveric specimen were randomly allocated to either four- or six-strand transosseous suture repair. Specimen underwent preconditioning cyclical loading and then load to failure. RESULTS: The six-strand repair had a significantly higher maximum load to failure compared with the four-strand repair (mean difference = 319.3 N [57.9%], p = 0.03). There was no significant difference in gap length after cyclical loading or at max load. There were no significant differences in mode of failure. CONCLUSION: Utilizing a six-stand transosseous patella tendon repair construct with one additional suture increases overall construct strength by over 50% compared with a four-strand construct.

Suture Anchor Fixation Has Less Gap Formation and No Difference in Complications or Revisions for Patellar Tendon Repair: A Systematic Review.

PURPOSE: To evaluate the literature on suture anchor (SA) usage for patellar tendon repair, summarize the overall biomechanical and clinical outcomes, and assess whether the cumulative research supports the adoption of this technique compared with transosseous (TO) repair. METHODS: A systematic literature review using the Preferred Reporting Items for Systematic and Meta-Analyses guidelines was performed. Multiple electronic databases were searched to identify studies focusing on surgical outcomes of patellar tendon repair with suture anchor usage. Cadaver and animal biomechanical studies, technical studies, and clinical studies were included. RESULTS: A total of 29 studies met the inclusion criteria: 6 cadaver, 3 animal, 9 technical, and 11 clinical reports. Four of the 6 cadaver studies and 1 of the 2 animal studies found significantly less gap formation from SA than from TO repair. Average gap formation in human studies ranged from 0.9 to 4.1 mm in the SA group compared with 2.9 to 10.3 mm in TO groups. Load to failure was significantly stronger in 1 of 5 cadaver studies and 2 of 3 animal studies, with human studies SA load to failure ranging from 258 to 868 N and TO load to failure ranging from 287 to 763 N. There were 11 clinical studies that included 133 knees repaired using SA. Nine studies showed no difference between complication rate or risk for reoperation, where one study reported a significantly lower re-rupture rate after SA repair compared with TO repair. CONCLUSIONS: SA repair is a viable option for patellar tendon repair and could have several advantages over TO repair. Multiple studies indicate that SA repair has less gap formation during biomechanical testing compared with TO repair in human cadaver and animal models. No differences in complications or revisions were found in the majority of clinical studies. CLINICAL RELEVANCE: Both animal and human models suggest SA fixation has potential biomechanical benefits when compared with TO tunnels for patellar tendon repair, whereas clinical studies show no difference in complications and revisions postoperatively.

The impact of bone graft type used to fill bone defects in patients undergoing ACL reconstruction with bone-patellar tendon-bone (BPTB) autograft on kneeling, anterior knee pain and knee functional outcomes.

PURPOSE: Multiple different materials are used for filling bone defects following bone-patellar tendon-bone (BPTB) graft ACL reconstruction surgery. The theoretical objective being to minimize kneeling pain, improve clinical outcomes and reduce anterior knee pain following surgery. The impact of these materials is assessed in this study. METHODS: A prospective monocentric cohort study was conducted from January 2018 to March 2020. There were 128 skeletally mature athletic patients who underwent ACL reconstruction using the same arthroscopic-assisted BPTB technique, with a minimum follow-up of two years identified in our database. After obtaining approval from the local ethics committee, 102 patients were included in the study. Patients were divided into three groups based on type of bone substitute. The Bioactive glass 45S5 ceramic Glassbone™ (GB), collagen and hydroxyapatite bone void filler in sponge form Collapat® II (CP), and treated human bone graft Osteopure®(OP) bone substitutes were used according to availability. Clinical evaluation of patients at follow-up was performed using the WebSurvey software. A questionnaire completed in the 2nd post-operative year included three items: The ability to kneel, the presence of donor site pain, and the palpation of a defect. Another assessment tool included the IKDC subjective score and Lysholm score. These two tools were completed by patients preoperatively, and postoperatively on three occasions (6 months, 1 year, and 2 years). RESULTS: A total of 102 patients were included in this study. In terms of Kneeling pain, the percentage of GB and CP patients' who kneel with ease were much higher than that of OP patients (77.78%, 76.5% vs 65.6%, respectively). All three groups experienced an important increase in IKDC and Lysholm scores. There was no difference in anterior knee pain between the groups. CONCLUSION: The use of Glassbone® and Collapat II® bone substitutes reduced the incidence of kneeling pain compared to Osteopure®. There was no influence of the bone substitute type on the functional outcome of the knee or on the anterior knee pain at two years of follow.

Management of Patellar Tendinopathy.

Patellar tendinopathy is a common pathology typically seen in athletes involved in repetitive explosive jumping and running activities. Also known as jumpers' knee, it is commonly seen in high-level basketball players. Typically, athletes continue to play with symptoms, which can be aggravated and progress to partial patellar tendon tears. When partial patellar tendon tears occur, prolonged recovery and decreased performance is commonly seen. The pathology and treatment can be frustrating for both the athlete and medical provider. Patellar tendinopathy typically does not involve inflammation but rather microinjury to the tendon fibers, which leads to mucoid degeneration, necrosis, and loss of transitional fibrocartilage. When partial tendon tears do occur, the typical location is posteromedially adjacent to the patella. Treatment involves a stepwise approach starting with nonoperative means, including activity modification, nonsteroidal anti-inflammatories, and physical therapy focused on eccentrics. Extracorporeal shock wave treatments and injections with platelet-rich plasma or bone marrow aspirate concentrate should be considered, with evolving literature to support their use. Ultrasound percutaneous tendon scrapping with a needle supplemented with the aforementioned injections is an emerging treatment option that the authors have found to be helpful, although further studies are required. Surgical intervention is considered after failure of nonoperative treatments, and typically occurs in tears greater than 50% of the tendon thickness and in tendons with increased thickness (>8.8 mm). Open or arthroscopic debridement can be considered, with no studies showing superior outcomes with either technique; however, no high-quality comparison studies exist. The authors prefer an open technique where, much like a bone-patellar tendon-bone harvest, the unhealthy proximal tendon and bone are excised with then closure of the healthy tendon with absorbable sutures. Suture anchor repair may also be used when necessary. In a recent systematic review, surgical management of patellar tendinopathy has been shown to result in improved patient-reported outcomes with return to sport at high levels.1 Treatment for the difficult and sometimes frustrating pathology of patellar tendinopathy continues to evolve, with biologic and less-invasive ultrasound-based treatments showing promise, and surgical intervention providing reliable outcomes.

Patellar Tendon Rupture During Postoperative Physiotherapy for Crouch Gait: A Case Report.

INTRODUCTION: A 14-year-old adolescent girl with spastic diplegic cerebral palsy underwent bilateral distal femur extension osteotomy and patellar tendon plication. Two and a half months after surgery, during physiotherapy, she sustained mid-substance tear of the left patellar tendon. The girl was successfully managed with patellar tendon repair and augmentation with tensor fascia lata autograft. CONCLUSION: Patellar tendon rupture during rehabilitative physiotherapy after patellar tendon plication surgery is rare. Postoperative protocols in patients with cerebral palsy are crucial and should progress gradually to improve knee range of motion. This report highlights that patellar tendon repair with fascia lata augmentation yields good outcome.

AN INTRATENDINOUS GANGLION CYST OF THE PATELLAR TENDON: A RARE CAUSE OF ANTERIOR KNEE PAIN.

Ganglion cysts in the knee region can manifest as anterior knee pain. Unlike synovial cysts, these lesions lack synovial epithelial lining and occur secondary to mucoid degeneration of connective tissue because, often in response to chronic irritation and repetitive traumas. However, an intratendinous location is a rare finding. In the knee region, infrapatellar fat pad, the alar folds, and the anterior cruciate ligament are recognized to degenerate into ganglion. There are few case reports describing an involvement of the patellar tendon. We present the clinical case of a 72 years old male patient suffering from anterior knee pain attributed to an intratendinous ganglion cyst of the patellar tendon, obviously after a single traumatic event. After aspiration of the ganglion cyst the patient reported no complaints, and there has been no recurrence during the latest follow-up examination.

Time to treat the tendon rupture induced by surgery: early hypertrophy of the patellar tendon graft site predicts strong quadriceps after ACLR with bone-patellar tendon-bone autograft.

PURPOSE: Quadriceps dysfunction is ubiquitous after anterior cruciate ligament reconstruction, especially when using bone-patellar tendon-bone (BPTB) autografts. The role of patellar tendon hypertrophy after graft harvest on knee extensor strength is unknown. The purpose of this study was to determine the predictive ability of patellar tendon (PT) and quadriceps muscle (Quad) cross-sectional area (CSA) on knee extensor strength 1-2 months after ACLR using BPTB autografts. METHODS: This is a cross-sectional analysis of a cohort 1-2 months after ACLR using BPTB autograft. Peak knee extensor torque, and PT and Quad CSA measured using ultrasound imaging, were collected in 13 males and 14 females. Simple linear regressions compared quadriceps strength index (QI) against limb symmetry index (LSI) in PT and Quad CSA. Multiple linear regressions with sequential model comparisons predicting peak knee extensor torque were performed for each limb. The base model included demographics. Quad CSA was added in the first model, then PT CSA was added in the second model. RESULTS: Both PT (p < 0.001, R2 = 0.693) and Quadriceps CSA (p = 0.013, R2 = 0.223) LSI had a positive linear relationship with QI. In the involved limb, addition of PT CSA significantly improved the model (R2 = 0.781, ΔR2 = 0.211, p for ΔR2 < 0.001). In the uninvolved limb, the addition of Quad CSA improved the model, but the addition of PT CSA did not. CONCLUSION: PT LSI was more predictive of QI than Quad CSA LSI. Involved limb PT CSA mattered more in predicting peak knee extensor torque than did Quad CSA, but in the uninvolved limb, Quad CSA was the most important predictor of peak knee extensor torque. Graft site patellar tendon hypertrophy is key for strong quadriceps early after ACLR. Early targeted loading via exercise to promote healing of the graft site patellar tendon may bring patients a step closer to winning their battle against quadriceps dysfunction. LEVEL OF EVIDENCE: Level I.