Current Concepts and the Role of Surgery in the Treatment of Jumper's Knee

Current Concepts in Patellar Tendinopathy: An Overview of Imaging, Pathogenesis, and Nonoperative and Operative Management

» Approximately 1 in 3 high-impact athletes develops patellar tendinopathy (PT), with the proximal insertion of the patellar tendon being the most commonly affected anatomical site.» Nonoperative treatment options are effective in reducing pain and restoring functionality in most patients with PT. However, operative intervention should be considered when conservative management fails.» A comprehensive review of the literature on surgical procedures, including both open and arthroscopic approaches, was conducted with a specific focus on clinical outcomes and return to sports.» Both open surgery and arthroscopic surgery for PT have demonstrated favorable success rates and return-to-sport outcomes, with arthroscopic treatment potentially expediting the recovery process.

Narrative: Review of Anterior Knee Pain Differential Diagnosis (Other than Patellofemoral Pain)

PURPOSE OF REVIEW

This review presents a framework for constructing a differential diagnosis for chronic anterior knee pain associated with overuse other than patellofemoral pain. Traumatic, systemic, and pediatric injuries will not be covered.

RECENT FINDINGS

From superficial to deep, the anterior knee can be conceptually organized into four layers: (1) soft tissue, (2) extensor mechanism, (3) intracapsular/extrasynovial, and (4) intra-articular. From superficial to deep, diagnoses to consider include bursitis, patellar and quadriceps tendinosis, fat pad impingement, and plica syndromes.

Differences in the Development of Fibrocartilage Layers in the Quadriceps Tendon and Patellar Tendon Insertions in Rabbits: A Quantitative Study

Background

Differences in the development of fibrocartilage layers in quadriceps tendon (QT) and patellar tendon (PT) insertion sites are unclear. Because the mechanical environments for the QT and PT are different, the development of the QT and PT insertions may differ.

Purpose

To investigate differences in the development of fibrocartilage layers in the QT and PT insertion sites in rabbits through use of quantitative morphometric evaluations.

Study Design

Descriptive laboratory study.

Methods

This study included 54 male Japanese White rabbits. Animals were euthanized at ages 1 day and 1, 2, 3, 4, 6, 8, 12, and 24 weeks (n = 6 for each age). Chondrocyte number, proliferation, apoptosis, sex-determining region Y box 9 (Sox9)-positive rates, safranin O-stained glycosaminoglycan (GAG) areas, tidemark length, insertion width, and patellar length were evaluated and compared with the same parameters at age 24 weeks and between QT and PT insertion sites.

Results

Chondrocyte proliferation was low up to age 2 weeks for QT insertion and low up to 1 week for PT insertion. Chondrocyte apoptosis was high at 1 day and Sox9 expression was low up to 1 week for PT insertion. Sox9 expression was higher in QT than in PT insertion at age 12 weeks. The high chondrocyte count continued to age 1 day in PT insertion and up to 6 weeks in QT insertion. The chondrocyte number was higher in QT than in PT insertion at age 2 weeks. The period of thicker GAG lasted from 2 to 8 weeks in PT insertion and from 1 to 12 weeks in QT insertion. GAG thickness in QT insertion was higher than in PT insertion at age 4 and 12 weeks.

Conclusion

Development of fibrocartilage layers in QT and PT insertion sites was completed at age 24 weeks in rabbits. However, the period of high chondrocyte count and period of thicker GAG were longer in QT than in PT insertion up to 12 weeks.

Clinical Relevance

Development of fibrocartilage layers in QT and PT insertions differed in rabbits. Our results may contribute to the development of appropriate treatments based on age and the development of methods for regeneration of the insertion.

Results of Arthroscopic Treatment of Chronic Patellar Tendinopathy

BACKGROUND

The surgical treatment of chronic patellar tendinopathy could be open or arthroscopic. A general agreement on the best surgical treatment option is still lacking.

PURPOSE

The aim of our study was to evaluate the clinical results after a minimally invasive arthroscopic treatment of chronic patellar tendinopathy including a resection of the lower patellar pole.

METHODS

The study included 14 patients with a mean age of 26 years and chronic patellar tendinopathy refractory to non-operative treatment of more than 6 months. All patients underwent arthroscopic debridement of the adipose tissue of the Hoffa's body posterior to the patellar tendon, debridement of abnormal patellar tendon and resection of the lower patellar pole. Preoperative and postoperative evaluation was undertaken using clinical examination, magnetic resonance imaging (MRI) and the Lysholm and Victorian Institute of Sport Assessment-Patella (VISA-P) scores. Return to sports and postoperative complications were also assessed. The mean follow-up was 12.2 ± 0.9 months.

RESULTS

All 14 patients continued with sport activities, but only 12 of them (85.7%) achieved their presymptom sporting level. The median time to return to preinjury level of activity was 3.9 ± 0.8 months. Patients showed a major improvement in the mean Lysholm score from 51.1 ± 3.8 to 93.4 ± 4.2 (p=0.001) and in the mean VISA-P score from 42.1 ± 3.5 to 86.7 ± 8.4 (p=0.001) There were no postoperative complications.

CONCLUSION

We found that this arthroscopic technique gives reduced morbidity and satisfactory outcome resulting in significantly faster recovery and return to sports in patients with chronic patellar tendinopathy.

Quadriceps tendinopathy: a review, part 2-classification, prognosis, and treatment

Overuse injuries of the extensor mechanism of the knee are common in both athletes and non-athletes and usually occur during activities associated with repetitive loading, stress, and knee extension. Numerous reports have been published describing extensor mechanism injuries in athletes, but there is a paucity of studies that focus on quadriceps tendinopathy in the non-athlete population. In addition, there is no universally accepted classification system for tendon pathology. Therefore, we performed a comprehensive literature review of these studies. This review consists of 2 parts. In the previous part we reviewed: (I) epidemiology and (II) diagnosis of quadriceps tendinopathy in the athlete as well as the general population. In this part we discuss: (I) classification; (II) prognosis; and (III) treatment results.

Proposing a Patellar Tendinopathy Screening tool following a systematic review

BACKGROUND

Patellar tendinopathy (PT) is an overuse injury of the knee. The mechanism of injury is associated with repetitive stress on the patellar tendon of the knee as a result of explosive movement. Patellar tendinopathy is prevalent in all populations and is associated with intrinsic and extrinsic risk factors.

OBJECTIVES

Primarily, the objective was to report on the intrinsic and extrinsic risk factors for PT, entailing a systematic review of the literature; the secondary objective was to use these risk factors to compile a proposed PT screening tool from the review and standard outcome measures.

METHOD

A systematic review was undertaken according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Elimination criteria of the articles included duplicates, titles, abstracts and methodological quality. The evidence was collected, characterised with regard to the intrinsic and extrinsic risk factors and summarised descriptively.

RESULTS

The search yielded 157 feasible articles prior to commencement of article elimination. Six articles were included with a mean methodological quality score of 69%. Eight intrinsic and five extrinsic risk factors were identified. These identified risk factors are all relevant to the pathology and formed the basis for a proposed PT screening tool. The Victorian Institute of Sports Assessment for Patellar Tendinopathy Questionnaire, Visual Analog Scale and the Pain Provocation Test are also included in the proposed test.

CONCLUSION

Intrinsic and extrinsic risk factors for PT were identified, and consequently, the proposed PT screening tool was formulated for possible future testing in appropriate studies.

CLINICAL IMPLICATIONS

Prevention of PT through intrinsic and extrinsic risk factor identification, and implementation in the clinical setup as a possible outcome measurement tool with which to verify functional improvement in PT rehabilitation.