Surgical treatment of patellar tendon rupture after total knee arthroplasty with a double-row repair method using the hamstring tendons: A novel technique with functional results

BACKGROUND

Patellar tendon rupture (PTR) is extremely rare but serious complication after primary or revision total knee arthroplasty. Due to the serious failure rates of end-to-end repair techniques, various augmentation techniques have been described. In this study, the results of patients with PTR after reconstruction using our own technique with semitendinosus (ST) and gracilis tendons taken from the affected side were evaluated retrospectively.

METHODS

A total of 14 patients, whose diagnosis was made based on physical examination and clinical findings, and supported radiologically (ultrasonography), were included in the study. In these patients, reconstruction was performed using double-row repair technique with the ST and gracilis tendons. Active-passive knee joint range of motion, active knee extension loss, and the Caton-Deschamps index at preoperative and final follow-up visits were compared. Tegner-Lysholm knee score and Kujala score were used to evaluate functional results.

RESULTS

In 14 patients (8 women and 6 men) with a mean age of 68.1 years, the median time between injury and surgery was 6.6 weeks. In all patients, the rupture was in the distal part of the patellar tendon. While the median preoperative Caton-Deschamps index was 1.8, the postoperative median value was found to be 1.25 after an average follow-up of 3.8 years (P = .014). The median preoperative knee extension loss decreased from 25° to 5° postoperatively. Tegner-Lysholm knee score and Kujala score of the patients at their last follow-up were significantly increased (P < .01).

CONCLUSION

For PTR developing after total knee arthroplasty, the double-row reconstruction technique with ST and gracilis tendons is effective.

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.

Ultrasound- and Doppler-Guided WALANT Arthroscopic Surgery for Patellar Tendinopathy with Partial Rupture in Elite Athletes-A 2-Year Follow-Up of a Prospective Case Series

Background and Objectives: Patellar tendinopathy is difficult to treat, and when combined with partial rupture, there are additional challenges. The aim of this study was to evaluate the subjective outcome and return-to-sport status after ultrasound (US)- and colour doppler (CD)-guided wide awake local anaesthetic no tourniquet (WALANT) arthroscopic shaving in elite athletes. Material and Methods: Thirty Swedish and international elite athletes (27 males) with a long duration (>1 year) of persistent painful patellar tendinopathy in 35 patellar tendons, not responding to non-surgical treatment, were included. All patients were treated with the same protocol of arthroscopic shaving, including bone removal and debridement of partial rupture, followed by at least 3 months of structured rehabilitation. The VISA-P score and a study-specific questionnaire evaluating physical activity level and subjective satisfaction with the treatment were used for evaluation. Results: At the 2-year follow-up (mean 23, range 8-38 months), 25/30 patients (29/35 tendons) were satisfied with the treatment result and had returned to their pre-injury sport. The mean VISA-P score increased from 37 (range 7-69) before surgery to 80 (range 44-100) after surgery (p < 0.05). There was one drop-out (one tendon). There were no complications. Conclusions: US- and CD-guided WALANT arthroscopic shaving for persistent painful patellar tendinopathy, including bone removal and debridement of partial rupture, followed by structured rehabilitation showed good clinical results in the majority of the elite-level athletes.

A Novel Tendon Injury Model, Induced by Collagenase Administration Combined with a Thermo-Responsive Hydrogel in Rats, Reproduces the Pathogenesis of Human Degenerative Tendinopathy

Patellar tendinopathy is a common clinical problem, but its underlying pathophysiology remains poorly understood, primarily due to the absence of a representative experimental model. The most widely used method to generate such a model is collagenase injection, although this method possesses limitations. We developed an optimized rat model of patellar tendinopathy via the ultrasound-guided injection of collagenase mixed with a thermo-responsive Pluronic hydrogel into the patellar tendon of sixty male Wistar rats. All analyses were carried out at 3, 7, 14, 30, and 60 days post-injury. We confirmed that our rat model reproduced the pathophysiology observed in human patients through analyses of ultrasonography, histology, immunofluorescence, and biomechanical parameters. Tendons that were injured by the injection of the collagenase-Pluronic mixture exhibited a significant increase in the cross-sectional area (p < 0.01), a high degree of tissue disorganization and hypercellularity, significantly strong neovascularization (p < 0.01), important changes in the levels of types I and III collagen expression, and the organization and presence of intra-tendinous calcifications. Decreases in the maximum rupture force and stiffness were also observed. These results demonstrate that our model replicates the key features observed in human patellar tendinopathy. Collagenase is evenly distributed, as the Pluronic hydrogel prevents its leakage and thus, damage to surrounding tissues. Therefore, this model is valuable for testing new treatments for patellar tendinopathy.

Bifocal avulsion fracture and fixation of the patellar tendon: a case report

Acute distal patella tendon avulsion from the tibial tubercle (TT) is a relatively rare injury that is usually described in the adolescents or elderly population in their 7th or 8th decades. Bifocal avulsion fractures of the patella tendon from the TT and the distal pole of the patella are exceptionally rare in adults. In this case report, we present a 52-year-old healthy old male who was treated for bifocal avulsion of the patellar tendon with open reduction and internal fixation augmented with two ULTRATAPE sutures. To our knowledge, this is the first case report to describe this injury in a healthy middle-aged patient.

Surgical treatment of chronic proximal patellar tendon tears grades 3 and 4 using augmentation with quadriceps tendon-bone graft

BACKGROUND

Chronic proximal patellar tendinosis with partial tendon tears represents a multifactorial overuse injury. Several surgical techniques have been described with various outcomes and the return to sports may fail.

HYPOTHESIS

Reconstruction of the proximal patellar tendon with augmentation using a quadriceps tendon-bone (QTB) graft improves knee function in patients presenting with proximal patellar tendinosis and partial tendon tears.

METHODS

Forty-seven patients (32 males, 15 females) with chronic proximal patellar tendinosis and tendon tears grade 3 and 4 were treated between 1992 and 2018. Patients were evaluated retrospectively using the Popkin-Golman (PG) MRI grading system and the removed tendon parts. The Tegner Activity Scale (TAS) and the Numerical Rating Scale (NRS) for pain were used as outcome measures before surgery and at follow up. Complete data were available in 100% of cases at 6 months follow up, and fifteen of them at later follow up.

RESULTS

The average follow up was 1.5 years (range, 0.5-16). The TAS improved from a mean preoperative score of 3.7 to a mean postoperative score of 9.1. The median NRS status decreased from an average of 6.4 to 1.1. Two patients needed additional arthroscopic scar tissue removal.

CONCLUSION

Reconstruction of proximal patellar tendon tears grades 3 and 4 with augmentation using a QTB graft is a valuable surgical salvage procedure in chronic cases. It improves knee function and yields good to excellent results in most cases including high level athletes. The use of MRI with the PG classification of tendon tears is highly recommended.

LEVEL OF EVIDENCE

Therapeutic case series, Level IV.

Clinical and biomechanical outcomes following patellar tendon repair with suture tape augmentation

PURPOSE

Patellar tendon ruptures (PTR) occur predominantly in middle-aged patients following indirect trauma. The aim of this study was to quantify the short-term results using a suture tape augmentation technique for the repair of PTR.

METHODS

All consecutive patients with acute (< 6 weeks) PTR who underwent suture tape augmentation between 03/2014 and 11/2019 at a single institution with a minimum follow-up of 12 months were retrospectively evaluated. Outcome measures included Visual Analog Scale (VAS) for pain, Tegner Activity Scale (TAS) and return to sport rates, Lysholm score, International Knee Documentation Committee subjective knee form (IKDC) as well as Knee Injury and Osteoarthritis Outcome Score (KOOS). Additionally, a standardized clinical examination and an isometric strength evaluation of knee extension and flexion were performed. It was hypothesized that high return to sport rates and good functional outcome would be observed and that the majority of patients would not present with a severe (> 20%) knee extension strength deficit when compared to the contralateral side.

RESULTS

A total of 7 patients (mean age 37.0 ± SD 13.5 years; 6 male/1 female) were available for final assessment at a median follow-up of 17.0 (25-75% IQR 16.0-77.0) months. Three injuries occurred during ball sports, two injuries occurred during winter sports, and one injury each occurred during a motorcycling and skateboarding accident. The average time between trauma and surgery was 4.7 ± 2.6 days. At follow-up, patients reported little pain (VAS: 0 [0-0.4]). Return to sport was possible for all patients 8.9 ± 4.0 months postoperatively at a high level (TAS: 7.0 [6.0-7.0]). Five patients (71.4%) returned to the preinjury level of play, and 2 (28.6%) did not return to the preinjury level of play. Patient-reported outcome measures were moderate to good (Lysholm score: 80.4 ± 14.5; IKDC: 84.2 ± 10.6; KOOS subscales: pain 95.6 ± 6.0, symptoms 81.1 [64.9-89.1], activities of daily living 98.5 [94.1-100], sport and recreation function 82.9 ± 14.1 and knee-related quality of life 75.9 ± 16.3). All patients were very satisfied (57.1%) or satisfied (42.9%) with the postoperative result. No postoperative complications were reported. Strength measurements revealed a severe knee extension deficit in 3 patients (42.9%), but no significant deficit of isometric knee extension or flexion strength in comparison with the contralateral side was observed overall (p > 0.05).

CONCLUSION

Suture tape augmentation in acute PTR repair leads to good functional outcome without major complications. Although a severe knee extension strength deficit may occur in some patients postoperatively, an excellent return to sports rate and high patient satisfaction can be expected nonetheless.

LEVEL OF EVIDENCE

Retrospective cohort study; III.

Delaminated Patellar Tendon Rupture in a Pediatric Patient: A Case Report

CASE

We present a 12-year-old boy with partial delamination of the patellar tendon in the coronal plane and bipolar avulsion fracture of the tibial tubercle and patella after a planting injury while skateboarding. Pediatric patellar tendon rupture with associated bipolar avulsion fractures is rare. Furthermore, to the best of our knowledge, a delamination injury pattern of the patellar tendon has not been described.

CONCLUSION

This type of extensor mechanism injury has not been reported in the literature. Repair with Krackow sutures and suture-bone tunnel technique, with consideration of the proximal tibial physis, is a safe and effective way to fix this unique pathology.

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.

Characteristics of multi-ligament knee injuries accompanied with patellar tendon disruption

PURPOSE

Patella tendon rupture with multi-ligament injury is a rare injury. We observed patients with patella tendon rupture (or patella inferior pole fracture) with multi-ligament injury. This study intends to inspect the mechanism of the injury and classify them.

METHODS

This is a case series involving patients from two hospitals. Twelve patients who had patella tendon rupture (PTR) with multi-ligament injury were studied.

RESULTS

The incidence of multi-ligament injury in patella tendon rupture patients found to be 13% in retrospective search. Two types of injury were observed. First type is relatively low energy injury involving ACL and patella tendon which does not involve rupture of PCL. Second type is high energy injury involving PCL and patella tendon. Treatment differed among the patients, due to severity of trauma. Two-staged operation was the basis of treatment. Patella tendon was repaired in first stage. Reconstruction of ligaments was done in second stage. The patients who had infection or stiffness did not have a second surgery.

CONCLUSION

Patella tendon rupture with multi-ligament injury can be classified into low energy rotational injury and high energy dashboard injury. Two-staged surgery is the basis of treatment.

Are Current Prophylactic Programs Effective in Preventing Patellar Tendinopathy in Athletes and Recruits? A Meta-Analysis and Trial Sequential Analysis

CONTEXT

Patellar tendinopathy (PT), or jumper's knee, is a chronic painful overuse patellar tendon injury. For PT, prevention is more important than treatment. However, there is still a lack of strong evidence to confirm the effectiveness of prevention.

OBJECTIVE

This study will analyze by meta-analysis the effect of a prophylactic program on high PT risk people (but without PT) in reducing PT occurrence.

DATA SOURCES

PubMed, Embase, the Cochrane Library, Scopus, and Ebscohost, from inception to January 11, 2022.

STUDY SELECTION

A study comparing the effects of prophylactic programs and controls on the risk of PT was included in the analysis. After a database search with search terms ((patellar tendinopathy) OR (jumper's knee) OR (patellar tendinitis) OR (patellar tendinosis) OR (patellar tendonitis)) AND ((Prevent*) OR (prophyla*)), a total of 1444 items were obtained. Of these, 11 studies with 6091 participants were eligible for inclusion in this meta-analysis.

STUDY DESIGN

Systematic review and meta-analysis.

LEVEL OF EVIDENCE

Level 2.

DATA EXTRACTION

The first author's name, publication year, study design, country, population, mean age, sex, prophylactic program, control, study duration, and the frequency or incidence of PT in each group were extracted.

RESULTS

A total of 11 articles were included in the analysis. Overall, no significant difference was considered in the risk of PT between the prophylactic program and control groups based on the random-effect model (odds ratio [OR], 0.85; 95% CI, 0.67, 1.08; P = 0.18). In the recruit subgroup, there was even a tendency to elevate the risk of PT occurrence after prophylaxis was executed (OR, 1.89; 95% CI, 0.68, 5.28; P = 0.22). In athletes, the prophylactic program tended to decrease the risk of PT compared with the control (OR, 0.81; 95% CI, 0.63, 1.04; P = 0.10); however, the difference was not statistically significant. Trial sequential analysis results suggested that prophylaxis may still be effective for athletes, but this needs to be confirmed with a larger sample size.

CONCLUSION

The risk of PT cannot be reduced with the current prophylactic program. However, for athletes, the negative results may be due to insufficient sample size.

Management of Extensor Mechanism Disruption After Total Knee Arthroplasty

Extensor mechanism disruptions following total knee arthroplasty are devastating injuries with complication rates following surgical intervention ranging from 25% to 45%. Primary repair with and without augmentation is appropriate in certain limited clinical settings. Allograft reconstruction has been a popular option; however, synthetic grafts are showing promise and good results. In this article the authors discuss an algorithm for treating these difficult injuries as well as detail the surgical techniques for each approach.

Association of COA1 with Patellar Tendonitis: A Genome-wide Association Analysis

PURPOSE

It is unknown why some athletes develop patellar tendinopathy and others do not, even when accounting for similar workloads between individuals. Genetic differences between these two populations may be a contributing factor. The purpose of this work was to screen the entire genome for genetic markers associated with patellar tendinopathy.

METHODS

Genome-wide association (GWA) analyses were performed utilizing data from the Kaiser Permanente Research Board (KPRB) and the UK Biobank. Patellar tendinopathy cases were identified based on electronic health records from KPRB and UK Biobank. GWA analyses from both cohorts were tested for patellar tendinopathy using a logistic regression model adjusting for sex, height, weight, age, and race/ethnicity using allele counts for single nucleotide polymorphisms. The data from the two GWA studies (KPRB and UK Biobank) were combined in a meta-analysis.

RESULTS

There were a total of 1670 cases of patellar tendinopathy and 293,866 controls within the two cohorts. Two single nucleotide polymorphisms located in the intron of the cytochrome c oxidase assembly factor 1 (COA1) gene showed a genome-wide significant association in the meta-analysis.

CONCLUSIONS

Genetic markers in COA1 seem to be associated with patellar tendinopathy and are potential risk factors for patellar tendinopathy that deserve further validation regarding molecular mechanisms.

Tenascin-C regulates migration of SOX10 tendon stem cells via integrin-α9 for promoting patellar tendon remodeling

Insufficient attention has been focused on the directional migration of SOX10+ tendon stem cells (STSCs) during tendon remodeling. Here, we investigate whether tenascin-C (TNC) promotes STSC motility and migration. Based on the hypothesis that TNCs induce STSC migration, RNA-sequencing (RNA-seq) was conducted, identifying 2107 differentially expressed genes (DEGs), of which 1272 were up-regulated and 835 down-regulated following treatment with TNC versus the control. The DEGs were principally involved in cell adhesion and cell membrane signal transduction. Highly enriched-related signaling included the PI3K-Akt, focal adhesion, and ECM-receptor interaction pathways. Protein interaction analysis established that TNC was positively correlated with ITGA9 (integrin-α9). Furthermore, TNC activated the phosphorylation levels of FAK and Akt, and knockdown of ITGA9 with siRNA revealed that TNC contributes to STSC migration via the targeting of ITGA9. In addition, in vivo administration of TNC promoted tissue regeneration of injured tendons. In conclusion, TNC regulated the migration of STSCs via ITGA9, thereby promoting the regeneration of tendon injuries.

[Total primary knee prosthesis in a patient with non-recent rupture of the patellar tendon, treated in 2 surgical times]

INTRODUCTION

Patellar tendon rupture has a higher prevalence in older patients related to systemic diseases such as rheumatoid arthritis, lupus erythematosus and those with prolonged treatment with corticosteroids or antibiotic therapy. It is caused by trauma with the knee in flexion accompanied by a contraction of the quadriceps or eccentric force, the diagnosis can be omitted in up to 38% of cases. Treatment of non-recent tendon ruptures is more difficult with end-to-end techniques are complicated and difficult to perform 45 days after injury due to quadriceps retraction, fibrosis, adhesion formation, and muscle hypotrophy. Treatment options are varied, ranging from autografts to synthetic grafts using bone tunnels and fixation anchors.

CASE REPORT

Our case is a 71-year-old patient with an 18-year-old patellar tendon rupture treated in two stages, starting with repairing the extensor apparatus with pes anserinus tendons, preserving their insertion and subsequently performing total knee replacement in a second surgical time and we show its evolution.

Multifocal Disruption of the Extensor Mechanism of the Knee: A Case Report

CASE

A 41-year-old man presented with a transverse patella fracture and proximal patellar tendon avulsion after a fall from standing. Disruption of the extensor mechanism of the knee at multiple points is rare. He was treated operatively for his patella fracture and patellar tendon avulsion but experienced early failure of the patellar tendon fixation requiring reoperation. Both components of injury ultimately healed, and he returned to function.

CONCLUSION

This case describes a rare presentation of an uncommon injury pattern affecting the extensor mechanism. This is the first report to describe multifocal failure of the extensor chain from a low-energy mechanism.

Rehabilitation of patellar tendinopathy

Patellar tendinopathy is a common musculoskeletal disorder characterized by progressive activity-related anterior knee pain and patellar tendon dysfunction. It is highly prevalent in sports which involve running and jumping. Various treatment methods are used in the management of PT including rest, activity modification, anti-inflammatory medication, injection therapies, taping, eccentric exercises, extra corporeal shock wave therapy, percutaneous electrolysis, and surgery. Even though various treatment options are available for patellar tendinopathy, no single method has proven to result in a consistent and near complete recovery in patients. Conservative management is considered to be the first line of treatment. This study presents an overview of the current practice about the management of patellar tendinopathy with an emphasis on rehabilitation. This review can act as a guide to sports medicine and rehabilitation professionals' decision making in the management of this disorder.

Plethora of Traumatic Lesions of Bilateral Knee Extensor Mechanism in Osteogenesis Imperfecta

INTRODUCTION

Injuries to the quadriceps extensor mechanism are rare in patients with Osteogenesis Imperfecta (OI). To the best of our knowledge, non-union of the patella in OI, either as an isolated problem or in combination with an acute fracture, has not been previously reported.

CASE REPORT

We describe how we surgically approached both the fracture and the non-union simultaneously. The surgical technique and steps are described in detail. Post-operative course was uneventful and the outcome was favorable, with full return of function for the patient.

CONCLUSION

A review of various knee extensor mechanism injuries in OI is described as illustrated in a single patient. The unusual simultaneous surgical treatment of a non-union and an acute fracture in the same patella shows that despite the severely compromised bone in this rare bone disease the bone still has a capacity to heal with a functional outcome.

Traumatic injury of the knee extensor mechanism in skeletally immature patients: Outcome and classification

BACKGROUND

The literature is limited on the etiology and outcome of acute traumatic knee extensor mechanism injuries in skeletally immature patients with lack of a reliable classification system.

METHODS

Data on patients who sustained an acute traumatic injury of the knee extensor mechanism were reviewed with a minimum of 12-month follow-up. Functional outcome was evaluated regarding knee active range of motion. Functional outcome was described using the Knee Society Score (KSS). Data were expressed as mean ± standard deviation.

RESULTS

Seventy-two patients with 74 knee extensor mechanism injuries were identified. The age at the time of injury was 13.9 ± 1.9 years. They included 59 injuries with tibial tubercle avulsion fracture, six injuries with patellar tendon avulsion without bone injury, six injuries with combined patellar tendon avulsion with tibial tubercle fracture, two injuries with sleeve fracture, and one injury with quadriceps tendon avulsion. According to our classification, type IB1 injury was the commonest injury (79.7%). The time to return to sports was 5.23 ± 2.98 months. The flexion was 128.7° ± 13.3°. A mean terminal extension lag of 5.6° was detected in three patients (4.1%). The KSS was 94.8 ± 8.1 and the functional outcome was graded excellent in 64 patients (88.9%), good in seven patients (9.7%), and fair in one patient (1.4%).

CONCLUSIONS

Traumatic injuries of the knee extensor mechanism in skeletally immature patients represent a wide variety of injuries including bony injuries in 82.4% of cases reviewed, tendinous injuries in 9.5%, and both bone and tendinous injuries in 8.1%. Our proposed classification system provides a more precise description of the injury pattern.

Paediatric conjoint bicondylar Hoffa fracture with patellar tendon injury: An unusual pattern of injury

Epiphyseal injuries of distal femur are rare with an incidence of 1%-6% among all physeal injuries. Prompt diagnosis and appropriate surgical treatment is crucial to achieve satisfactory functional outcomes. A conjoint bicondylar coronal split (Hoffa) fracture with complete transaction of ipsilateral patellar tendon has been reported in a 12 year old child. The injury was managed by open reduction and internal fixation and bone to tendon repair. This case emphasizes the need of accurate intraepiphyseal fixation for the management of these fractures in skeletally immature patients.

Relaxin inhibits patellar tendon healing in rats: a histological and biochemical evaluation

BACKGROUND

Female patients are more likely to have tendon injuries than males, especially those who has a higher concentration of relaxin. Previous studies have demonstrated that relaxin attenuates extracellular matrix (ECM) formation. However, the mechanism of relaxin on tendon repair remains unclear. We hypothesize that relaxin inhibits tendon healing by disrupting collagen synthesis.

METHODS

A patellar tendon window defect model was established using Sprague-Dawley rats. The center of the patellar tendon was removed from the patella distal apex and inserted to the tibia tuberosity in width of 1 mm. Then, the rats were injected with saline (0.2 μg/kg/day) or relaxin (0.2 μg/kg/day) for two and four weeks, which was followed by biomechanical analysis and histological and histochemical examination.

RESULTS

Mechanical results indicated that relaxin induces a significant decrease in tear resistance, stiffness, and Young's modulus compared to those rats without relaxin treatment. In addition, it was shown that relaxin activates relaxin family peptide receptor 1(RXFP1), disturbs the balance between matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteases (TIMPs), and reduces the deposition of collagen in injury areas.

CONCLUSIONS

Relaxin impairs tendon healing in rats. Also, relaxin might lead to tendon injury more commonly for females than males.

Intra-operative patellar fracture during chronic patellar tendon rupture reconstruction: salvage and prophylactic modified techniques

Management of chronic neglected patellar tendon rupture represents a challenging condition for the orthopedic surgeons to deal with due to many factors such as quadriceps muscle atrophy, superior migration of the patella, e.g., patella alta, peri-patellar adhesions and patellar tendon atrophy. Such difficulties might be further complicated by intra-operative patellar fracture during patellar tendon reconstruction. In the current article, the authors report (1) a salvage procedure for such devastating intra-operative complication, based on bypassing the patella and gaining the advantage of the quadriceps tendon for structural and functional restoration of the knee extensor mechanism, and (2) prophylactically a technical modification of patellar tendon reconstruction guarding against such inadvertent patellar fracture.

Combined avulsion fracture of the tibial tubercle and patellar tendon rupture in adolescents: a case report

Simultaneous occurrence of tibial tubercle fracture and patellar tendon avulsion is an extremely rare condition. However, they have become more frequent due to increased participation in sports at a younger age. Diagnosis is not always straightforward, and treatment consists of open reduction and internal fixation. Only a few case reports of such injuries were reported in the literature with limited information according to diagnoses, treatment, and outcome in adolescents.

[Patellar tendon rupture with distal closed fracture of the ipsilateral femur]

We here report the case of a 45-year old patient who had injured his right knee because of a road accident. The patient had right comminuted supracondylar femur fracture and ipsilateral patellar tendon rupture. This association is exceptional and no case has been reported in the literature. Targeted clinical and radiological diagnostic tests followed by early and suitable management based on internal osteosynthesis and suitable early functional rehabilitation enabled good long term outcome.

[Patellar tendon ruptures : Internal bracing and augmentation technique]

OBJECTIVE

To report a surgical technique for the treatment of patellar tendon ruptures augmented with an internal brace suture tape.

INDICATIONS

Acute patellar tendon ruptures, fractures of the distal patellar pole, chronic insufficiency of the patellar tendon or revision surgery for failed repairs.

CONTRAINDICATIONS

Severe damage to the surrounding soft tissue. Local infection. Life-threatening conditions.

SURGICAL TECHNIQUE

Direct longitudinal anterior approach to the patellar tendon. Two parallel transosseous bone tunnels are drilled in the patella and tibial tuberosity with a 2.4 mm drill bit. Two separate FiberTapes® (Arthrex, Naples, FL; USA) are shuttled through the proximal and distal bone tunnels around the tendon in "X" and "O" type configuration. Patellar height is reestablished under fluoroscopic control and both FiberTapes are tied down. Both tendon ends are debrided and readapted with absorbable sutures.

POSTOPERATIVE MANAGEMENT

Passive motion exercise to 90° of flexion from day 1. Partial load to 20 kg of body weight with knee in locked full extension brace during first 2 weeks. Isometric exercises from week 3. Passive flexion to 110° from week 4 (adapted to pain). Free active range of motion and weight bearing from week 7.

RESULTS

In more than 10 years of clinical application, positive results were continuously found in acute as well as chronic patellar tendon ruptures. These results are consistent with those in the current literature.

Surgical Management of Simultaneous Anterior Cruciate Ligament and Patellar Tendon Ruptures: A Systematic Review

This study performs a systematic review to determine (1) if a significant difference exists in return to preinjury activity level between one- and two-stage treatment of combined anterior cruciate ligament (ACL) and patellar tendon (PT) tears; and (2) if a significant difference exists in the number of postoperative complications between the two differing surgical treatment approaches. A systematic review was performed using Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines and registered on PROSPERO. MEDLINE, Cochrane Central Register of Controlled Trials, SCOPUS, and Sport Discus were searched for English language level I-IV evidence studies on either one- (simultaneous) or two-stage (sequential) surgical treatment of simultaneously sustained ipsilateral ACL and PT tears. The approach to initial evaluation, diagnosis, treatment, and outcomes were qualitatively analyzed. Methodological quality assessment of all included studies was completed using the Methodological Index for Non-randomized Studies (MINORS). The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) tool was used to assess quality of evidence and provide strength of recommendation. Statistical analyses were done using Fischer's exact test. Eleven articles (18 patients; 83% males; mean age, 31.1 ± 10.1 years; mean follow-up, 2.2 ± 1.7 years; and mean MINORS 7.8/16) were analyzed. Eight patients had a one-stage procedure (primary PT repair and ACL reconstruction), and 10 patients underwent a two-stage procedure (primary PT repair first followed by ACL reconstruction) with mean 28 ± 45.7 weeks (5 weeks-3 years) between surgeries. The rate for return to preinjury activity level after surgery was not significantly different between one- (88%) and two-stage (100%) (p = 0.444). There was a significantly higher complication rate (p = 0.023) in the one-stage (stiffness, instability, and patella baja) versus two-stage surgery (no complications). There was no significant difference in return to preinjury activity level between one- and two-stage PT repair and ACL reconstruction. However, the one-stage combined surgery had a significantly higher complication rate compared with two-stage surgery. The level of evidence is IV.

Platelet-rich plasma in tendon-related disorders: results and indications

PURPOSE

Platelet-rich plasma (PRP) is currently the most exploited strategy in the clinical practice to provide a regenerative stimulus for tendon healing. The aim of the present study was to systematically review the available evidence on the treatment of the main tendon disorders where PRP is currently applied.

METHODS

A systematic review of the literature was performed on the use of PRP as a treatment for tendinopathies focusing on the following sites: Achilles tendon, patellar tendon, rotator cuff tendons, and lateral elbow tendons. The following inclusion criteria for relevant articles were used: clinical trials written in English language up to 21 June 2016 on the use of PRP in the conservative or surgical treatment of the aforementioned tendinopathies.

RESULTS

The research identified the following clinical trials dealing with the application of PRP in the selected tendons: 19 papers on patellar tendon (6 being RCTs: 4 dealing with PRP conservative application and 2 surgical), 24 papers on Achilles tendon (4 RCTs: 3 conservative and 1 surgical), 29 on lateral elbow tendons (17 RCTs, all conservative), and 32 on rotator cuff (22 RCTs: 18 surgical and 3 conservative).

CONCLUSION

Patellar tendons seem to benefit from PRP injections, whereas in the Achilles tendon, PRP application is not indicated neither as a conservative approach nor as a surgical augmentation. Lateral elbow tendinopathy showed an improvement in most of the high-level studies, but the lack of proven superiority with respect to the more simple whole-blood injections still questions its use in the clinical practice. With regard to rotator cuff pathology, the vast majority of surgical RCTs documented a lack of beneficial effects, whereas there is still inconclusive evidence concerning its conservative application in rotator cuff disorders.

LEVEL OF EVIDENCE

Systematic review of level I-IV trials, Level IV.

This Surgeon Puts Broken Spurs Back in the NBA Saddle

David R. Schmidt, MD, team physician for the San Antonio Spurs.

[Jumper's Knee]

Zusammenfassung. Sportliche Aktivitäten mit Sprungabläufen stellen für die Kniegelenke eine mechanische Herausforderung dar. Häufig projizieren sich chronisch auftretende, atraumatische Beschwerden auf den Patellaunterpol, welcher pathomorphologisch eine patellare Tendinopathie entspricht. Extrinsische und intrinsische Risikofaktoren können unterschieden werden. In der klinischen Untersuchung zeigt sich ein meist unauffälliges Knie mit einer Druckdolenz am kaudalen Teil der Kniescheibe beim Übergang zum Ligamentum patellae. In der Bildgebung ist sonografisch ein degenerierter Sehnenanteil der tiefen Patellarsehne zu erkennen, der magnettomografisch mit Hyperintensität des Hoffa-Körpers einhergehen kann. Abhängig von der klinischen Entwicklung wird das Jumper’s Knee nach Blazina Grad I–IV eingeteilt. Bis zu 90 % der Patienten können konservativ therapiert werden. Operativ stehen offene und arthroskopische Verfahren mit ordentlichem Resultat zur Verfügung.

Spontaneous bilateral rupture of patellar ligament

We present the case of a 44-year-old patient with spontaneous bilateral ruptures of the proximal part of the patellar ligament. There were no identified specific risk factors for tendon ruptures. The diagnosis of bilateral patellar tendon rupture was confirmed in the initial physical examination with unambiguous x-ray diagnosis of patella alta. The second day after the injury, the patient underwent bilateral reinsertion of the rupture with transosseous suture (FiberWire) through tunnels in patella, together with the protection of the primary repairs using cerclage wires. Due to re-rupture of the patella ligament of the right knee two weeks later, revision procedure was carried out. That consisted of resuture of the tendon by the original method and augmentation using the semitendinosus and gracilis tendons. Postoperatively, both knees were fixed in orthoses for 12 weeks, flexion to 60° was allowed after 6 weeks, and flexion beyond 90° after 9 weeks. After one year from injury, the patient had an active bilateral full extension. The range of the right knee flexion was 125° and 130° on the left. The range of the right knee flexion was 125° and 130° on the left. The patient subjectively felt his right knee to be more stable. The clinical results of surgical treatment of the bilateral rupture ligamentum patellae tendons depend on early surgical intervention and post-operative rehabilitation. Augmentation of the tendon with autograft, allograft, or synthetic materials is indicated in the case of re-ruptures, late sutures and in cases of deficient quality of the tendon. We found no similar case described either in the Slovak or Czech literature. Key words: knee injuries patellar ligament rupture semitendinosus gracilis reconstruction.

Distal patellar tendon avulsion in association with high-energy knee trauma: A case series and review of the literature

BACKGROUND

Patellar tendon rupture is rare in the general population. Typically, failure occurs proximally or at the mid-substance. Distal avulsion from the tibial tubercle in adults is rare and not well described in the orthopedic literature.

METHODS

We present the largest series of patients with distal patellar tendon injury with associated multi-ligamentous disruption of the knee. A series of six patients with distal patellar tendon avulsion were identified at a single institution. The cases were reviewed and are presented.

RESULTS

Each case of distal patellar tendon rupture was associated with high-energy trauma to the knee. There was multi-ligamentous disruption in all cases, associated tibial plateau fracture in one case, and a compartment syndrome diagnosed in another. We propose that distal patellar tendon avulsion is a distinct pathology of the extensor mechanism in healthy adults. When present, it should prompt clinicians to assess patients for occult knee dislocation, monitor their neurovascular status, and obtain an MRI to evaluate for associated multi-ligamentous injury.

CONCLUSION

We propose a modification to the Schenk classification to include extensor mechanism injury to help guide steps of operative intervention.

[Simultaneous Traumatic Rupture of Patellar Ligament and Contralateral Rupture of Quadriceps Femoris Muscle]

Our paper presents a unique case of a 64-year-old patient after a fall, treated with oral antidiabetic drugs for type II diabetes mellitus. Following a series of examinations, a bilateral injury was diagnosed - patellar ligament tear on the right side and rupture of quadriceps femoris muscle on the left side. It is a rare injury, complicated by simultaneous involvement of both knee joints. The used therapy consisted of a bilateral surgery followed by gradual verticalisation, first with the support of a walking frame and later with the use of forearm crutches. During the final examination, the patient demonstrated full flexion at both knees, while an extension deficit of approx. 5 degrees was still present on the left side. The right knee X-ray showed a proper position of the patella after the removal of temporary tension band wire. Although the clinical results of operative treatment of both the patellar ligament rupture and rupture of quadriceps femoris muscle are in most cases good, early operative treatment, proper technique and post-operative rehabilitation are a prerequisite for success. Key words: knee injuries, patellar ligament, quadriceps muscle, rupture.

Chronic Quadriceps Tendon Rupture After Total Knee Arthroplasty Augmented With Synthetic Mesh

Tear of the quadriceps tendon after revision or primary total knee arthroplasty is a rare complication, but when it occurs, this injury has serious functional consequences. In complete tears, the outcome of direct repair is unpredictable, and several authors recommend that the suture should be reinforced. Several techniques have been described, including the use of autografts, allografts, and synthetic mesh. The goal of this study was to assess the outcomes of a reconstruction technique augmented with synthetic mesh. A retrospective study was performed involving 3 patients who had chronic partial quadriceps tendon tear after total knee revision. In 2 cases, proximal quadriceps release was performed. When conservative management failed, surgical reconstruction with suture reinforced with synthetic mesh was attempted. The knee was immobilized in full extension for 6 weeks after the surgical procedure. A minimum follow-up of 12 months was required to assess results. All reconstructions showed clinical success at a mean follow-up of 19 months. Mean Knee Society Score improved from 55.7 to 87.3, with average postoperative extensor lag of 3.3° (range, 0°-10°). The mean visual analog scale pain score was 2.3 (range, 0-4). No complications were reported. Synthetic mesh has previously been shown to be an effective treatment for patellar tendon repairs after total knee replacement, but there have been few articles on quadriceps rupture. Surgical reconstruction with synthetic mesh is a viable option that provides good functional outcomes in chronic quadriceps tendon rupture after total knee arthroplasty. [Orthopedics. 2017; 40(1):38-42.].

Comparison of desired radiographic advancement distance and true advancement distance required for patellar tendon-tibial plateau angle reduction to the ideal 90° in dogs by use of the modified Maquet technique

OBJECTIVE To evaluate the validity of 2 radiographic methods for measurement of the tibial tuberosity advancement distance required to achieve a reduction in patellar tendon-tibial plateau angle (PTA) to the ideal 90° in dogs by use of the modified Maquet technique (MMT). SAMPLE 24 stifle joints harvested from 12 canine cadavers. PROCEDURES Radiographs of stifle joints placed at 135° in the true lateral position were used to measure the required tibial tuberosity advancement distance with the conventional (A^M) and correction (A^E) methods. The MMT was used to successively advance the tibial crest to A^M and A^E. Postoperative PTA was measured on a mediolateral radiograph for each advancement measurement method. If none of the measurements were close to 90°, the advancement distance was modified until the PTA was equal to 90° within 0.1°, and the true advancement distance (TA) was measured. Results were used to determine the optimal commercially available size of cage implant that would be used in a clinical situation. RESULTS Median A^M and A^E were 10.6 mm and 11.5 mm, respectively. Mean PTAs for the conventional and correction methods were 93.4° and 92.3°, respectively, and differed significantly from 90°. Median TA was 13.5 mm. The A^M and A^E led to the same cage size recommendations as for TA for only 1 and 4 stifle joints, respectively. CONCLUSIONS AND CLINICAL RELEVANCE Both radiographic methods of measuring the distance required to advance the tibial tuberosity in dogs led to an under-reduction in postoperative PTA when the MMT was used. A new, more accurate radiographic method needs to be developed.

Medial Gastrocnemius Flap for Reconstruction of the Extensor Mechanism of the Knee Following High-Energy Trauma. A minimum 5 year follow-up

INTRODUCTION

The purpose of this study was to assess the medium-term results of reconstruction of the extensor mechanism using the medial gastrocnemius while also providing soft tissue coverage.

MATERIALS AND METHODS

This retrospective review consisted of a consecutive series of four patients (age 28-40 years) with complex high energy traumatic injuries to lower extremity including both soft tissue loss and disruption of the knee extensor mechanism. The medial gastrocnemius rotational flap was used to reconstruct the patellar tendon and restore soft tissue coverage simultaneously. Range of motion and extensor lag; functional recovery was judged by return to work and sports activity. Validated measures included the Oxford Knee Score, Knee Injury and Osteoarthritis Outcome Score, and the modified Cincinnati Score.

RESULTS

At the final follow up was 61.5 (57-66) months after reconstruction, the mean SF 12 physical component score ranged from 21.7 to 56.8 with a median of 55.3; the mental component from 42.8 to 60.7 with a median of 58.6. The KSS knee score ranged from 50 to 78 with a median of 68; the function score from 65 to 90 with a median of 85. The Oxford knee score ranged from 22 to 45 with a median of 33.5. The KOOS ranged from 28 to 82.7 with a median of 73.7 and the modified Cincinnati score from 38 to 82 with a median of 76.5. Knee range of motion ranged from 0 to 120°. Of the four patients three returned to working fulltime in their profession and returned to sports, including mountain biking and fitness training.

CONCLUSIONS

For severe traumatic knee injuries with the combination of soft tissue defects and disruption of the extensor mechanism, the medial gastrocnemius flap provides an excellent reconstructive option to address both problems simultaneously. The results of this small case series support the use of this limb salvage technique.

Stepwise Differentiation of Mesenchymal Stem Cells Augments Tendon-Like Tissue Formation and Defect Repair In Vivo

: Tendon injuries are common and present a clinical challenge, as they often respond poorly to treatment and result in long-term functional impairment. Inferior tendon healing responses are mainly attributed to insufficient or failed tenogenesis. The main objective of this study was to establish an efficient approach to induce tenogenesis of bone marrow-derived mesenchymal stem cells (BMSCs), which are the most common seed cells in tendon tissue engineering. First, representative reported tenogenic growth factors were used as media supplementation to induce BMSC differentiation, and the expression of teno-lineage transcription factors and matrix proteins was compared. We found that transforming growth factor (TGF)-β1 significantly induced teno-lineage-specific gene scleraxis expression and collagen production. TGF-β1 combined with connective tissue growth factor (CTGF) elevated tenomodulin and Egr1 expression at day 7. Hence, a stepwise tenogenic differentiation approach was established by first using TGF-β1 stimulation, followed by combination with CTGF for another 7 days. Gene expression analysis showed that this stepwise protocol initiated and maintained highly efficient tenogenesis of BMSCs. Finally, regarding in situ rat patellar tendon repair, tendons treated with induced tenogenic BMSCs had better structural and mechanical properties than those of the control group, as evidenced by histological scoring, collagen I and tenomodulin immunohistochemical staining, and tendon mechanical testing. Collectively, these findings demonstrate a reliable and practical strategy of inducing tenogenesis of BMSCs for tendon regeneration and may enhance the effectiveness of cell therapy in treating tendon disorders.

SIGNIFICANCE

The present study investigated the efficiency of representative tenogenic factors on mesenchymal stem cells' tenogenic differentiation and established an optimized stepwise tenogenic differentiation approach to commit tendon lineage differentiation for functional tissue regeneration. The reliable tenogenic differentiation approach for stem cells not only serves as a platform for further studies of underlying molecular mechanisms but also can be used to enhance cell therapy outcome in treating tendon disorders and develop novel therapeutics for tendon injury.

Biomechanical Assessment of Patellar Advancement Procedures for Patella Alta

Crouch gait deformity is common in children with cerebral palsy and often is associated with patella alta. Patellar tendon advancement typically is used to correct patella alta and restore normal knee mechanics. The purpose of this study was to determine the mechanical strength of surgical constructs used for fixation during patellar advancement procedures. This study used a cadaveric model to determine which of 3 surgical techniques is biomechanically optimal for patellar tendon advancement in treating patella alta. Twenty-four human cadaveric knees (8 per group) were prepared using 1 of 3 different common surgical techniques: tibial tubercle osteotomy, patellar tendon partial resection and repair at the distal patella, and patellar tendon imbrication. The patella was loaded from 25 to 250 N at 1 Hz for 1000 cycles. A significant difference in patella displacement under cyclical loading was found between surgical techniques. Tibial tubercle osteotomy exhibited significantly less displacement under cyclical loading than distal patella excision and repair (P<.0001) or imbrication (P=.0088). Imbrication exhibited significantly less displacement than distal patella excision and repair (P=.0006). Tibial tubercle osteotomy survived longest. Based on failure criteria of 5 mm of displacement, tibial tubercle osteotomy lasted between 250 and 500 cycles. The other 2 techniques failed by 25 cycles. This study offers quantitative evidence regarding the relative mechanical strength of each construct and may influence choice of surgical technique. [Orthopedics. 2016; 39(3):e492-e497.].

Avulsion Fracture of the Tibial Tubercle Associated With Patellar Tendon Avulsion

Avulsion fractures of the tibial tubercle in adolescent athletes are uncommon injuries, believed to be a result of forceful extension of the knee against a fixed leg. Concomitant injury to the ipsilateral patella tendon is even more rare, with few cases reported in the literature. The mechanisms responsible for this association are not well understood. The significance of this double insult to the knee extensor mechanism is the potential deleterious effect of misdiagnosis and/or mismanagement. In this case report, the pathophysiology, mechanism of injury, classification, diagnosis, and management of concomitant injury are reviewed. [Orthopedics. 2016; 39(3):e561-e564.].

Chronic Knee Dislocation After Total Knee Arthroplasty

Knee dislocation after total knee arthroplasty (TKA), although rare, is a dangerous injury that can lead to neurovascular compromise and permanent disability. Chronic dislocation after TKA is even less common and is defined as dislocation that is present for 4 weeks or more. There are few reports of its management. Chronic dislocation may be complicated further by concomitant extensor mechanism disruption, ligamentous instability, and/or capsular contracture. This article describes 3 cases of chronically dislocated TKAs and the challenges encountered in treating this difficult problem. A higher level of constraint was required to maintain knee stability, and an extensor mechanism allograft was needed in 2 of the 3 reported patients. The preferred technique at the authors' institution is a complete allograft composite, tensioned in full extension. In the setting of a chronically dislocated TKA, the authors now recommend revision surgery with an enhanced measure of constraint (constrained condylar device or hinged knee prosthesis), reconstruction of the extensor mechanism when necessary, and restoration of the joint while compensating for concomitant bony defects. Even when surgeons follow these principles, it is important to inform the patient that long-term outcomes will likely be inferior to those of revision surgery for other causes.

Knee extensor mechanism allograft reconstruction following chronic disruption

The management of chronic extensor mechanism disruption can be complex. One of the options is allograft reconstruction. The goal of this study was to present the surgical procedure and provide preliminary results with this technique. The allograft uses the whole extensor mechanism (anterior tibial tubercle, patellar ligament, patella, quadriceps tendon). The native patella can be completely removed if the quality of the bone is poor, otherwise a bone groovecan be created to receive the allograft. The allograft is tightly tensioned with the knee in full extension. This surgical technique was performed 5 times with a minimum follow-up of 1 year. Active extension was recovered in all cases. The mean postoperative KOOS was 55.5 the IKS function score was 68.5 and the IKS knee score was 83.

Improved biomechanical and biological outcomes in the MRL/MpJ murine strain following a full-length patellar tendon injury

Musculoskeletal injuries greatly affect the U.S. population and current clinical approaches fail to restore long-term native tissue structure and function. Tissue engineering is a strategy advocated to improve tendon healing; however, the field still needs to establish biological benchmarks for assessing the effectiveness of tissue-engineered structures. Investigating superior healing models, such as the MRL/MpJ, offers the opportunity to first characterize successful healing and then apply experimental findings to tissue-engineered therapies. This study seeks to evaluate the MRL/MpJ's healing response following a central patellar tendon injury compared to wildtype. Gene expression and histology were assessed at 3, 7, and 14 days following injury and mechanical properties were measured at 2, 5, and 8 weeks. Native patellar tendon biological and mechanical properties were not different between strains. Following injury, the MRL/MpJ displayed increased mechanical properties between 5 and 8 weeks; however, early tenogenic expression patterns were not different between the strains. Furthermore, expression of the cyclin-dependent kinase inhibitor, p21, was not different between strains, suggesting an alternative mechanism may be driving the healing response. Future studies will investigate collagen structure and alignment of the repair tissue and characterize the complete healing transcriptome to identify mechanisms driving the MRL/MpJ response.

Medial patellofemoral ligament tears in the setting of multiligament knee injuries rarely cause patellar instability

BACKGROUND

Multiligament knee injuries (MLKIs) can also involve the medial patellofemoral ligament (MPFL), but there is a paucity of information regarding prevalence and relevance of MPFL involvement in this setting.

PURPOSE

(1) To identify the prevalence of MPFL injury in MLKIs, (2) to determine whether an MPFL tear results in symptomatic patellar instability, and (3) to report clinical and functional outcomes of patients with and without MPFL tears after MLKI surgical reconstruction.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

The records of all patients who underwent surgical reconstruction of MLKI (defined as a grade 3 injury of ≥2 ligaments) at a single institution from 2007 to 2010 were reviewed. Age, sex, knee dislocation classification (according to Schenck), and MRI findings were documented. All preoperative MRI scans were reviewed by an experienced musculoskeletal radiologist to determine the presence or absence of MPFL involvement. If an MPFL tear was present, its anatomic location and severity as well as the presence of patellar or lateral femoral condyle bone bruises were documented. Inclusion criteria included (1) MLKI treated at a single institution, (2) presence of MPFL tear on preoperative MRI, and (3) minimum 2-year clinical follow-up. Patellar instability symptoms were assessed with the Kujala Knee Questionnaire. Functional outcomes were measured using the International Knee Documentation Committee (IKDC) score. IKDC scores were compared between patients who sustained MLKIs with and without MPFL tears. There were 21 patients in each group.

RESULTS

Over the 4-year study period, 30 of 51 patients (59%) treated surgically for a MLKI had MRI evidence of an MPFL tear. Nine were lost to follow-up, leaving 21 patients for review. There were 13 complete (62%), 5 high-grade partial (24%), and 3 partial (14%) MPFL tears. Sixteen of 21 tears (76%) occurred at the proximal third, with the remainder exhibiting diffuse signal abnormality consistent with tearing throughout the length of the MPFL. The superficial medial collateral ligament was involved in all patients. In no case was the MPFL repaired or reconstructed. At mean follow-up of 3.6 years (range, 2.0-5.7 years), only 1 of 21 patients (5%) complained of patellofemoral instability symptoms whereas 20 of 21 patients (95%) did not experience patellar subluxation or dislocation. No significant difference was found when IKDC scores were compared between patients with and without an MPFL tear (mean ± SD, 65.5 ± 22.9 vs 79.4 ± 16.1; P = .07).

CONCLUSION

MPFL tears occur frequently in patients with MLKI but rarely cause instability. In the majority of cases, MPFL tears do not need to be addressed at the time of surgery.

One-year follow-up of platelet-rich plasma infiltration to treat chronic proximal patellar tendinopathies

Infiltration of Platelet-Rich Plasma (PRP) may be considered as a recent therapeutic option for chronic tendinopathies. The aim of this study is to evaluate the clinical status and the return to sports activities in patients with chronic proximal patellar tendinopathies. Twenty subjects with chronic proximal patellar tendinopathy benefited from 1 infiltration of PRP coupled with a standardized eccentric rehabilitation. The follow-up (up to 1 year) was assessed by means of a Visual Anologue Scale (VAS), the International Knee Documentation Committee (IKDC) form and the Victorian Institute of Sport Assessment (VISA-P) score. Moreover, subjects had to answer an information questionnaire concerning their life and sports activities. Seventy percents of the patients reported a favourable evolution with decrease of pain, and returned to sports activities. With time, VAS dropped significantly and both IKDC and VISA-P scores improved also significantly. This study confirms that a local injection of PRP coupled with a program of eccentric rehabilitation for treating a chronic jumper's knee, improves pain symptoms and the functionalities of the subjects' knee up to 1 year after injection.

Recurrent patellar tendon rupture in a patient after intramedullary nailing of the tibia: reconstruction using an Achilles tendon allograft

Various complications after intramedullary (IM) nailing of the tibia have been reported, the most common of which are anterior knee pain and symptoms similar to patella tendonitis. Complete rupture of the patellar tendon after IM nailing of the tibia has been reported on 2 occasions, in conjunction with predisposing patient factors, such as systemic disease or a proud tibial nail. Patellar tendon ruptures are disabling injuries that can be technically difficult to repair because of the poor quality of remaining tendon tissue, quadriceps muscle atrophy and/or contracture, and scar-tissue formation. Many methods have described the surgical reconstruction of the knee extensor mechanism, which is most commonly performed after total knee arthroplasty. We report the successful surgical and clinical outcome of patellar tendon reconstruction using an Achilles tendon allograft in a patient subject to late and recurrent ruptures after IM nailing of the tibia through a mid-patellar tendon-splitting approach. Seven months after tendon reconstruction, the patient exhibited full knee flexion, an extension lag of 10º, 4/5 quadriceps strength, and return to her baseline ambulatory status.

Repair and augmentation of a spontaneous patellar tendon rupture in a patient with Ehlers-Danlos syndrome: a case report

INTRODUCTION

Disruption of the knee extensor mechanism is a serious disorder that requires prompt treatment. It often occurs in the form of a patellar tendon rupture. It may occur in association with systemic disease or after administration of corticosteroids or fluoroquinolones. These conditions can cause tendon weakness, and consequent ruptures usually require both repair and augmentation. This paper reports on repair and augmentation for treating patellar tendon rupture in patients with Ehlers-Danlos syndrome (EDS).

CASE REPORT

We report a patellar tendon rupture in a 27-year-old man with EDS, which occurred in the midsubstance of the patella. As the patient has tendon weakness, extensive repair will increase the risk of patella baja, and the use of end-to-end suturing technique alone will not be enough to prevent a rupture recurring; however, augmentation could be used to address the tendon weakness. Repair of the rupture and augmentation with hamstring tendon was performed. One year after the surgery, the patient was able to move his knee joint without pain and had an active range of motion of 0° (passive 20°)-145°. He was able to perform a straight leg raise without an extension lag.

CONCLUSIONS

Repair and augmentation with hamstring tendon was an effective treatment option for patellar tendon rupture in a patient with EDS.

Bilateral extensor mechanism disruption after total knee arthroplasty in two morbidly obese patients

Disruption of the extensor mechanism as a result of patellar tendon or quadriceps tendon rupture is an uncommon but devastating complication after total knee arthroplasty. Treating a disrupted extensor mechanism can be challenging, particularly in patients who are morbidly obese, due to an increased risk of postoperative complications. Therefore, despite the debilitating nature of extensor mechanism disruption, many community surgeons do not feel comfortable pursuing more complex cases like revision total knee arthroplasty with extensor mechanism allograft on morbidly obese patients, and consequently many of these patients are referred to tertiary-care centers for reconstruction secondary to the complexity of this patient cohort. The authors report 2 cases of bilateral extensor mechanism disruption after total knee arthroplasty in patients who are morbidly obese. One patient experienced trauma leading to her initial rupture; however, her contralateral atraumatic disruption was subsequently diagnosed at a later date. The second patient did not experience trauma leading to either of her extensor mechanism disruptions. Despite substantial medical comorbidities and morbid obesity, revision total knee arthroplasties with extensor mechanism allografts were recommended in both cases in a staged bilateral fashion. The surgical technique is described and the unique challenges afforded by the marked obesity are detailed. The current literature on this subject is reviewed. Despite early complications related to recumbency, this report serves as an example of successful repairs of extensor mechanism disruptions in patients who are morbidly obese, suggesting that extensor mechanism allograft is viable even in patients with high risk of complications.

Effects of low-intensity pulsed ultrasound on new trabecular bone during bone-tendon junction healing in a rabbit model: a synchrotron radiation micro-CT study

This study was designed to evaluate the effects of low-intensity pulsed ultrasound on bone regeneration during the bone-tendon junction healing process and to explore the application of synchrotron radiation micro computed tomography in three dimensional visualization of the bone-tendon junction to evaluate the microarchitecture of new trabecular bone. Twenty four mature New Zealand rabbits underwent partial patellectomy to establish a bone-tendon junction injury model at the patella-patellar tendon complex. Animals were then divided into low-intensity pulsed ultrasound treatment (20 min/day, 7 times/week) and placebo control groups, and were euthanized at week 8 and 16 postoperatively (n = 6 for each group and time point). The patella-patellar tendon specimens were harvested for radiographic, histological and synchrotron radiation micro computed tomography detection. The area of the newly formed bone in the ultrasound group was significantly greater than that of control group at postoperative week 8 and 16. The high resolution three dimensional visualization images of the bone-tendon junction were acquired by synchrotron radiation micro computed tomography. Low-intensity pulsed ultrasound treatment promoted dense and irregular woven bone formation at week 8 with greater bone volume fraction, number and thickness of new trabecular bone but with lower separation. At week 16, ultrasound group specimens contained mature lamellar bone with higher bone volume fraction and thicker trabeculae than that of control group; however, there was no significant difference in separation and number of the new trabecular bone. This study confirms that low-intensity pulsed ultrasound treatment is able to promote bone formation and remodeling of new trabecular bone during the bone-tendon junction healing process in a rabbit model, and the synchrotron radiation micro computed tomography could be applied for three dimensional visualization to quantitatively evaluate the microarchitecture of new bone in bone-tendon junction.

[Idiopathic bilateral patellar tendon rupture]

In the absence of systemic disease, specific treatment or sport tendonitis, simultaneous bilateral patellar tendon rupture is rare. Often missed on the first glance, it represents a diagnostic difficulty that should not be overlooked at the initial medical visit. The loss of active extension of the lower limb and a radiographic patella alta, even in a bilateral context, should raise suspicion of this diagnosis. It is then necessary to search for predisposing causes and to evoke the differential, or frequently associated, diagnoses. The present report illustrates these diagnostic difficulties and summarizes some clinical considerations that might help to avoid neglecting these different elements at the first medical visit (positive diagnosis, associated lesions, favouring factors).