We present a case of a neglected patellar tendon rupture, misdiagnosed as an anterior cruciate ligament tear, in a 12-year-old child with open physis without an avulsion fracture. The patient was treated with an ipsilateral hamstring tendon autograft with preserved distal insertions, a transpatellar tunnel, and a transtibial fixation. At the final follow-up, the patient had a full range of motion and a fully functional knee. The described technique results in complete muscle strength, full range of motion, and pain-free gait. It can be used in chronic patellar tendon ruptures and is a valuable addition to the therapeutic quiver for this type of injury.

UNASSIGNED: The phenomenon of a floating patella or ipsilateral bifocal rupture of the extensor apparatus is an extremely rare injury, with few cases reported in the literature. The aim of this case study is to report an unprecedented event: the simultaneous trans-tendinous rupture of both quadriceps and patellar tendons in a young adult without predisposing factors, emphasizing the need for awareness in diagnosis and management, and suggesting a new avenue for research in prevention and rehabilitation.
METHODS: We report the case of a 35-year-old patient with no significant medical history, who experienced this injury following a sudden start in a sprint without prior warm-up. The clinical examination revealed a swollen, painful knee with active extension deficit, patellar ascent, and a sub patellar hiatus. Magnetic Resonance Imaging (MRI) confirmed a trans-tendinous rupture of both the patellar and quadriceps tendons.
UNASSIGNED: Tendon repair was performed using end-to-end sutures and a figure-8 reinforcement with the semitendinosus tendon, along with gracilis plastie to strengthen the patellar tendon repair. This methodological approach is discussed in the context of its effectiveness and potential implications for future surgical management of similar injuries.
CONCLUSIONS: After a 12-month follow-up, the patient exhibited highly satisfactory results, resuming both professional and sporting activities. To our knowledge, this is the first published case of a trans-tendinous rupture of the extensor apparatus tendons. This observation serves as a reference in understanding the mechanism and surgical management of such lesions, emphasizing the need for further research and clinical vigilance in similar cases.

UNASSIGNED: To review reliable techniques for reconstructing or repairing chronic patella tendon tears and describe the unique case report of chronic patellar tendon tear with heterotopic ossification (HO).
UNASSIGNED: A 47-year-old male presented with chronic patellar tendon tears with HO, resulting in an inability to extend the right knee fully. Krackow suture repair augmented by autograft semitendinosus and gracilis was employed after debriding intra-substance patella tendon HO and fibrotic tissue. The repair was augmented using a method described by Chen et al. Postoperative recovery was uneventful, and the patient demonstrated an excellent Knee Society Score (86/100) at 6 months of follow-up. Proximal migration of the patella, poor tissue quality, scar tissue formation, and quadriceps atrophy pose unique challenges in managing chronic patellar tendon tears.
UNASSIGNED: HO increased the probability of patella baja after the reconstruction. To alleviate that, precise pre-op planning, careful method selection, and proper execution of the selected method are very important. A comprehensive review of 14 different methodologies for managing chronic patellar tendon tears, comprising eight case series and six case reports, was conducted. The selection of an appropriate technique should be based on individual patient characteristics, resource availability, and the surgeon\'s expertise.

The purpose of this systematic review is to report outcomes and complications following the reconstruction of chronic patellar tendon ruptures. Four databases (Cochrane Database of Systematic Reviews, PubMed, Embase, MEDLINE) were searched from inception to July 2021. Inclusion criteria included articles that (1) analyzed outcomes and complications following chronic patellar tendon reconstruction (>4 weeks from injury to repair), (2) were written in English, (3) greater than five patients, and (4) a minimum 2-year follow-up. Exclusion criteria included (1) non-original research and (2) patellar tendon repair/reconstruction with prior total knee arthroplasty. Data on outcome metrics and complications were extracted from the included studies and reported in a qualitative manner. Nine studies (number of patients = 96) were included after screening. Seven studies analyzed autograft reconstruction, and three of those seven studies analyzed reconstructions with additional augmentation. The remaining two studies evaluated reconstruction utilizing a bone-tendon-bone (BTB) allograft. Four of the autograft studies (n=40 patients) showed a range of post-operative mean Lysholm scores of 74-94. Additionally, four studies reported a post-operative extensor lag of 0-3°. Post-operative protocol for autograft studies included delayed motion and was either contained to a bivalved cast or a hinged knee brace for six weeks. The two allograft studies reported a range of mean Lysholm scores from 62 to 67, and each immobilized the leg in full extension until six weeks. While chronic patellar tendon ruptures are a rare injury of the extensor mechanism, there are viable options for reconstruction. Overall, chronic patellar tendon ruptures reconstructed with both autograft and allograft will provide fair to good outcomes with low complication rates. Following surgery, immobilization for at least six weeks should be emphasized to protect the graft and optimize patient outcomes.

Patellar tendon rupture is a rare but serious complication resulting in loss of knee extension that may develop during and after total knee arthroplasty and negatively affects the patient\'s quality of life. There are a number of surgical options available, from primary repair to reconstruction. Peroneus longus tendon autograft has begun to be used for knee extensor mechanism repair in recent years. In this case report, we aimed to present the case of a patient with traumatic patellar tendon rupture after revision knee arthroplasty. In conclusion, patellar tendon reconstruction using peroneus longus tendon autograft can be considered a successful method in selected patients following knee arthroplasty. It allows early rehabilitation via stable graft fixation and provides good clinical and functional outcomes in the late period.

The extensor mechanism of the knee can be damaged due to various modes of injury, which, in most cases, will require urgent surgical intervention for repair. Single patellar tendon ruptures are uncommon, but simultaneous bilateral events are even rarer and have been scarcely reviewed in English literature. Research in this area is mainly confined to case series, with some literature reviews but no evidence of more substantial analysis. Therefore, this systematic review was done to analyse the existing literature on bilateral simultaneous patellar tendon ruptures and propose a systematic and standardised approach to diagnosing and managing these injuries. A systematic review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The search terms included \'bilateral patellar tendon rupture\', \'bilateral\', \'patellar\', \'tendon\' and \'rupture\'. Three independent reviewers conducted searches in PubMed, OvidSP for Medline, Embase and the Cochrane Library using the same search strategy. The eligibility criteria included studies on bilateral concomitant patellar tendon rupture published in English. Bilateral simultaneous patellar tendon ruptures of traumatic and atraumatic origin in human patients were included. The study types comprised case reports and literature reviews. The key limitation of this study was the low number of patients covered by the eligible literature. Patellar tendon ruptures are a rare and scarcely documented injury, and there is a need for studies with a high level of evidence, especially regarding surgical treatment choice and methods, as well as post-operative management, which could potentially lead to improved outcomes in the management of this injury.

Alkaptonuria (AKU) is a rare hereditary disorder of tyrosine degradation. The disorder is characterized by the accumulation of a pigment called homogentisic acid. Its accumulation can lead to the breakdown of connective tissue, including tendons. This report presents a 46-year-old male with a history of bilateral total knee arthroplasty (TKA) who sustained bilateral patellar tendon rupture after an acute injury. A single-stage bilateral knee revision with direct repair of the extensor mechanism augmented with Achilles allograft was performed. The procedure was successful, and the patient had an excellent post-operative outcome at one year post-operatively. This case attempts to highlight the possible complications from AKU in order to better counsel patients with this condition who are undergoing TKA.

UNASSIGNED: Rupture to the patellar tendon caused by athletic activities is rare, but if not treated promptly, it can lead to unfavorable results such as quadriceps contracture, residual weakness, and reduced knee flexibility.
METHODS: A female patient who injured her knee seven months ago while twisting it experienced pain, instability, and tested positive for the anterior drawer and Lachman tests. Radiology results showed a complete tear of the anterior cruciate ligament (ACL) and a partial tear of the patellar tendon on the MRI scan of the right knee. We used a direct end-to-end approximation technique for the patellar tendon, with augmentation through the transosseous site at the patella proximally and tibial tubercle distally, without using a graft. The outcome was good, and this is the first reported case of a successful patellar tendon reconstruction without using implants, synthetic augmentation, or graft.
UNASSIGNED: This technique could be a promising alternative to repair a chronic patellar tendon rupture without using expensive methods. The use of fiber tape augmentation can be a practical solution for treating a neglected patellar tendon rupture in conjunction with aligamentous injury that requires graft repair.
CONCLUSIONS: The use of fiber tape augmentation might be an alternative method for treating a neglected patellar tendon rupture with concurrent ligament injury needing graft repair. We believe that this technique is easily reproducible and warrants further investigation.

A combination of tibial tuberosity (TT) fracture (TTF) along with patellar tendon (PT) rupture (PTR) is rare. We report a 15-year-old male who presented to our ED with acute knee pain and an inability to actively extend the knee after jumping during a basketball game. Diagnosis of simultaneous PTR is crucial as it changes clinical management. It is, therefore, important to maintain a high index of suspicion for the combination of TTF and PT injury.

The management of extensor mechanism lesions after total knee replacement is still associated with an unacceptably high complication rate, especially in its chronic setting. In this study, we report on 4 patients with chronic (> 3 months) patellar tendon rupture after knee arthroplasty, who were treated with a novel procedure of staged patella advancement prior to reconstruction with autografts. Initially, a unilateral frame was applied connecting the patella with the tibial shaft. The construct allowed for gradual distal advancement of the patella based on the Ilizarov principles. After achieving the desired patella height, the frame was removed, and the patellar tendon was reconstructed with hamstrings. All four patients experienced a significant improvement in extensor lag by a mean of 38.0°, while Knee society scores increased by a mean of 38.5 units. No substantial loss in active knee flexion was observed. Our findings suggest that our technique yields favorable outcomes in patients with patellar tendon disruption in the setting of a total knee arthroplasty.