Fifteen-year follow-up of arthroscopic partial meniscectomy

Long-term clinical and radiological outcomes after arthroscopic partial meniscectomy on stable knees are better for traumatic tears when compared to degenerative lesions: A systematic review

PURPOSE

An arthroscopic partial meniscectomy (APM) for degenerative meniscus lesions and traumatic meniscus tears are two distinct entities and their long-term outcomes are rarely reported. The aim of this review was to compare the long-term (clinical and radiological) results of APM performed on stable knees for traumatic tears (TT) or degenerative lesions (DL).

METHODS

Pubmed, Scopus and Embase databases were searched to identify relevant studies published between 2010 and 2023 using the keywords 'meniscectomy' OR 'meniscectomies' OR 'meniscal resection'. English-language, Levels I-IV evidence studies reporting either radiographic or clinical outcome measures with a minimum of 6 years' follow-up after APM were included. Studies including discoid meniscus, open meniscectomy, unstable knee and combination with other procedures were excluded. To rate the quality of evidence, the methodological index for non-randomized studies was used.

RESULTS

Thirty-two studies were included, with follow-up periods ranging from 6 to 22 years. Eleven studies dealt with TT with a mean age of 31.5 ± 6.6 years and a mean follow-up of 11.6 ± 6.9 years. At the last follow-up, radiographic osteoarthritis (OA) ranged from 36% to 76%, with an average rate of 48 ± 19%; functional scores ranged from 71 to 97, with a mean of 90 ± 4 for the Lysholm score, 86 ± 10 for the International Knee Documentation Committee (IKDC) and 94 ± 16 for the knee injury and osteoarthritis outcome (KOOS). Twenty-one studies dealt with DL with a mean age of 49.9 ± 7.2 years and a mean follow-up of 14.9 ± 6.3 years. At the last follow-up, radiographic OA ranged from 23% to 97%, with an average rate of 77 ± 28%; functional scores ranged from 40 to 87, with a mean of 79 ± 10 for the Lysholm score and 71 ± 16 for the IKDC.

CONCLUSION

Ten-year clinical outcomes of APM are better for TTs when compared to DLs. Rates of OA are difficult to compare but lower for TTs.

LEVEL OF EVIDENCE

Level IV.

Long Term Surgical and Radiological Outcome of Discoid Lateral Meniscus: An Updated Systematic Review

Purpose of the study

This study aimed to reach a consensus for ideal surgical treatment of discoid lateral meniscus (DLM) and to evaluate its long term surgical and radiological outcome.

Methods

All authors independently searched for peer reviewed publications with keywords like discoid lateral meniscus, tibial menisci abnormalities, tibial menisci surgery and clinical outcome and their representative Medical Subjects Headings (MeSH) in databases of PubMed, EBSCO, Cochrane Central Register of Controlled Trials, from inception to December 2022. Original articles in English language on discoid lateral meniscus reporting clinical, surgical, or radiological outcomes with five or more years of follow-up were included in this systematic review. Study details and outcome data were analysed according to the age, follow-up period, kind of surgery, DLM type, and alignment.

Results

Our search strategy yielded 654 articles in PubMed, 222 articles in EBSCO and 5 articles in CENTRAL i.e. a total of 881 articles. After detailed assessment and screening, 12 articles were included in the final analysis, which included 444 DLM cases. The mean patient age at surgery ranged from 9.9 to 35.9 years, and the mean follow-up period ranged from 5.2 to 16 years. Partial meniscectomy and meniscoplasty are the recommended treatment because of the concerns of degenerative arthritis development after the total and subtotal meniscectomies. Two studies have documented better results with meniscal allograft transplantation.

Conclusion

Satisfactory clinico-radiological outcome can be obtained after surgical treatment of discoid lateral meniscus with meniscus reshaping and repair of peripheral unstable part. Meniscal allograft transplantation (MAT) is gaining popularity in patients with total meniscectomy with satisfactory long term functional outcome.

Survivorship of 157 Arthroscopic Meniscal Allograft Transplants Using Bone Fixation at a Mean of 7 Years and Prognostic Factors Analysis

BACKGROUND

Meniscal allograft transplantation (MAT) is an accepted and effective treatment option in the context of unsalvageable menisci, particularly in young and active patients. It has been shown to reduce pain and improve knee function in previously symptomatic patients. However, there is still limited knowledge about the long-term survival rates of allografts, the durability of clinical results, and the influence of patient-specific parameters, such as leg alignment, tibial slope, and preoperative International Cartilage Regeneration & Joint Preservation Society (ICRS) grade.

PURPOSE

To determine (1) the long-term clinical success rate after MAT with bony fixation in a large, single-center cohort of consecutive patients, and (2) if patient-specific and procedural variables influence the clinical, anatomic, and subjective outcomes and risk of failure.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Data on 185 consecutive knees undergoing MAT in a single institution were prospectively collected and screened for inclusion in this study. The minimum follow-up time was 2 years. Radiographic variables (ICRS grade and Kellgren-Lawrence grade) were assessed preoperatively and at follow-up. Subjective patient-reported outcome measures (PROMs) (Lysholm score, Knee injury and Osteoarthritis Outcome Score [KOOS] including subscores, International Knee Documentation Committee [IKDC] score, and visual analog scale [VAS] score) were collected preoperatively and at follow-up. Clinical failure was defined as revision surgery due to graft failure or conversion to total knee arthroplasty. Anatomic failure was considered a tear covering >20% of the allograft, any peripheral tear, and unstable peripheral fixation leading to dislocation of the graft. Subjective failure was defined as Lysholm score ≤65. Preoperative tibial slope and leg alignment were assessed. Survival analyses were performed using the Kaplan-Meier estimate. Univariate and multivariate analyses were performed to determine risk factors for clinical and anatomic failure.

RESULTS

A total of 157 knees met inclusion criteria. After a mean follow-up time of 7 ± 3.5 years, 127 (80.9%) knees were free of clinical, anatomic, and subjective failure. Fourteen (8.9%) knees experienced clinical failure, 26 (16.6%) knees were identified as having experienced anatomic failure, and 13 (8.3%) patients experienced subjective failure with a reported Lysholm score of ≤65 at a mean follow-up of 7 years. Concurrent osteochondral allograft transplantation was identified as a predictor of both clinical (hazard ratio [HR], 4.55; 95% CI, 1.46-14.17; P = .009) and anatomic (HR, 3.05; 95% CI, 1.34-6.92; P = .008) failure. Cartilage damage of ICRS grade 3 or 4 of the index compartment conveyed an increased risk for clinical (HR, 3.41; 95% CI, 1.05-11.01; P = .04) and anatomic (HR, 3.04; 95% CI, 1.31-7.11; P = .01) failure. High-grade cartilage damage preoperatively (HR, 10.67; 95% CI, 1.037-109.768; P = .046), patient age >25 years (HR, 5.44; 95% CI, 0.120-246.070; P = .384), and a body mass index >30 (HR, 2.24; 95% CI, 0.748-6.705; P = .149) were associated with subjective failure. PROMs including KOOS and IKDC were significantly improved at final follow-up compared with preoperative scores across all measurements (P < .005).

CONCLUSION

MAT showed good to excellent clinical results at a mean follow-up of 7 years. Low ICRS lesion grade was associated with a higher clinical and anatomic survival rate. Patients with concurrent OCA transplantation are at a higher risk of clinical and anatomic failure, but still report significantly improved PROMs. These results suggest that MAT has a lasting beneficial effect both in isolation and in complex cases with ≥1 concurrent procedures.

High tibial osteotomy is equally effective for varus malaligned knees with either virgin or wrecked medial meniscus: An age and gender-matched secondary analysis of a Francophone Arthroscopy Society Symposium

INTRODUCTION

Despite the growing concept of meniscal preservation, partial meniscectomy could be the definitive procedure in specific scenarios. And total meniscectomy was once before a frequent procedure, with current sequelae of degenerate knees. High tibial osteotomy (HTO) is an effective treatment for patients suffering from unicompartmental degenerative changes, and substantial deformities. However, it is yet to be answered, whether HTO is similarly effective in both post-meniscectomy knees and knees with not previously operated meniscus.

HYPOTHESIS

Outcomes of HTO is similar with or without previous history of total or subtotal meniscectomy.

METHODS

This study compared the clinical and radiological outcomes of 41 patients who received HTO and had no previous history of surgery in the ipsilateral knee (group I), and 41 age, and gender-matched patients who had meniscectomy surgery in the ipsilateral knee (group II). Preoperatively and postoperatively, all patients were clinically evaluated; the visual analogue scale scores, Tegner activity score, and the Western Ontario and Macmaster University scores were reported. Radiographically, osteoarthritis grade and pre- and postoperative parameters were reported, including hip-knee-ankle angle, femoral mechanical angle, medial proximal tibial angle, joint line convergence angle, proximal posterior tibial angle, and limb length discrepancy. Perioperative details and complications were reported.

RESULTS

A total of 82 patients were included; group I (n=41) and group II (n=41). The mean age was 51.18±8.64 (27-68) and 90.24% were male. The duration since the onset of symptoms was longer in group II vs. group I, 43.34±41.03 versus 38.07±36.11months respectively. No significant differences in the clinical evaluation between the two groups with a greater proportion of patients demonstrating moderate degenerative changes. Similar preoperative and postoperative radiographic parameters were reported, in group I, Δ HKA was 7.19±4.14 versus 7.65±3.16 in group II. Preoperative pain VAS scores were slightly higher in group II vs. group I, 79.23±26.35 vs. 76.31±24.45, respectively. However, postoperatively, the pain scores significantly improved in group I vs. group II, 22.84±3.65 vs. 41.69±17.33, respectively. Tegner activity scores and WOMAC scores were comparable between both groups preoperatively and postoperatively. Only the WOMAC function scores were better in group I when compared to group II, 26.13±25.84 versus 20.01±17.98. All patients returned to work at an average of 0.82±0.38months.

CONCLUSION

Knee preservation with high tibial osteotomy is equally effective in managing unicompartmental degenerative changes in varus malaligned knees with either no previous history of meniscal surgeries or where a meniscal sacrifice was inevitable, either with subtotal or total meniscectomy.

LEVEL OF EVIDENCE

III, retrospective case-control study.

The Value of Ultrasound Diagnostic Imaging of Meniscal Knee Injuries Verified by Experimental and Arthroscopic Investigations

(1) Introduction: Meniscal knee injuries may develop as the result of trauma or overloading. Ultrasound imaging is an observer-dependent modality, meaning that the assessment of structural damage depends on the investigator's experience.. None of the published papers provides a standardized method for ultrasound examination of knee menisci. The main goal of this study is to realize and standardize ultrasound imaging diagnostics of meniscal knee injuries based on individual features of ultrasound presentation and to evaluate the applicability of this modality in clinical practice. (2) Material and methods: This study consisted of two anatomical parts, including a clinical part that started with clinical examination of 50 patients with suspected meniscal knee injuries. After this we performed ultrasound examinations in patients with positive clinical test results, using sonographic confirmation for inclusion in the next stage. Finally, knee arthroscopy by two physicians in an operating room was performed, with procedures documented through photographs and video recordings, and analytic material obtained from patients in the control group documented similarly. (3) Results: In the clinical part of the study, arthroscopic examination revealed 13 longitudinal injuries (corresponding to 36% of all injuries in the group), 14 multidirectional injuries (corresponding to 28% of all injuries), 3 radial injuries (corresponding to 6% of all injuries), and 20 oblique injuries (corresponding to 40% of all injuries). The analysis of the sensitivity and specificity of the diagnostic test in terms of recognizing actual meniscal injuries on the basis of full-thickness or partial-thickness delamination, meniscal cyst oedema, and articular space stenosis revealed that the presence of at least two of these three characteristics was associated with the sensitivity of 88% and the specificity of 86% relative to the number of actual meniscal injuries as seen in arthroscopic examination. (4) Conclusions: Research results confirm that clinical examination combined with ultrasound imaging is a very efficient tool for evaluation of meniscal injuries.

A Comparative Study on Outcomes of Partial Meniscectomy for Horizontal Cleavage Tear of Medial Meniscus: Complete versus Partial Resection of Inferior Leaf

The extent to which resection of unstable leaf should be performed in horizontal cleavage meniscus tear has not yet been elucidated. The purpose of this study was to compare the clinical outcomes of partial meniscectomy for horizontal cleavage tear of medial meniscus between complete resection of inferior leaf including the periphery up to the joint capsule and partial resection leaving stable peripheral torn meniscal tissue. A total of 126 patients who underwent partial meniscectomy for horizontal cleavage tear of medial meniscus were divided into two groups: group C (n = 34), treated with the complete resection of the inferior leaf; and group P (n = 92), treated with partial resection of the inferior leaf. The minimum follow-up duration was 3 years. Functional outcomes were evaluated using the Lysholm knee scoring scale, International Knee Documentation Committee (IKDC) subjective knee evaluation form, and knee injury and osteoarthritis outcome score (KOOS). Radiologic assessments were performed using the IKDC radiographic assessment scale and measurement of the height of the joint space in the medial compartment of the tibiofemoral joint. The functional outcomes including the Lysholm knee, IKDC subjective score, activities of daily living and sport and recreation subscale of KOOS were worse in group C than in group P (p < 0.001). The radiologic outcomes including postoperative IKDC radiographic scale (p = 0.003) and the postoperative joint space on the affected side (p < 0.001) were also worse in group C than in group P. In the horizontal cleavage tear of medial meniscus, complete resection of the inferior leaf including the periphery up to the joint capsule showed inferior clinical outcomes compared with partial resection leaving stable peripheral rim of torn meniscus at minimum 3-year follow-up. If the peripheral part of the inferior leaf is stable in horizontal cleavage tear of medial meniscus, partial resection of the inferior leaf preserving peripheral rim can be recommended.

Autologous semitendinosus meniscus graft significantly improves knee joint kinematics and the tibiofemoral contact after complete lateral meniscectomy

PURPOSE

The purpose of this study was to investigate the potential of a doubled semitendinosus (ST) and a single gracilis tendon (GT) lateral meniscus autograft to restore the knee joint kinematics and tibiofemoral contact after total lateral meniscectomy (LMM).

METHODS

Fourteen human knee joints were tested intact, after LMM and after ST and GT meniscus autograft treatment under an axial load of 200 N during full range of motion (0°-120°) and four randomised loading situations: without external moments, external rotation, valgus stress and a combination of external rotation and valgus stress using a knee joint simulator. Non-parametric statistical analyses were performed on joint kinematics and on the tibiofemoral contact mechanics.

RESULTS

LMM led to significant rotational instability of the knee joints (p < 0.02), which was significantly improved after ST autograft application (p < 0.04), except for knee joint flexions > 60°. The GT autograft failed to restore the joint kinematics. LMM significantly increased the tibiofemoral contact pressure (p < 0.03), while decreasing the contact area (p < 0.05). The ST autograft was able to restore the contact mechanics after LMM (p < 0.02), while the GT replacement displayed only an improvement trend.

CONCLUSION

The doubled ST lateral meniscus autograft improved the knee joint kinematics significantly and restored the tibiofemoral contact mechanics almost comparable to the native situation. Thus, from a biomechanical point of view, ST meniscus autografts might be a potential treatment alternative for patients who are indicated for meniscus allograft transplantation.

Benefits of Meniscal Repair in Selected Patients Aged 60 Years and Older

Background

Little is known about the benefits and outcomes of meniscal repair in patients older than 60 years.

Purpose

To (1) report the clinical and radiographic outcomes of meniscal repair in patients aged ≥60 years and compare them with matched patients who underwent meniscectomy and (2) identify procedural failures.

Study Design

Cohort study; Level of evidence, 2.

Methods

We included 32 knees in 32 patients aged ≥60 years (20 female, 12 male; mean age, 64.5 ± 4.6 years) who underwent meniscal repair surgery at a single medical institution between 2010 and 2020. Patients were matched according to age, sex, body mass index, and meniscal tear type with a comparison cohort who underwent meniscectomy (n = 49 patients [49 knees]; 32 female, 17 male). For all patients, demographic information, clinical history, physical examination findings, treatment details, and radiographic images were reviewed and analyzed. At final follow-up (mean, 42.2 months; range, 13-128 months), patients completed the 2000 International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form, Knee injury and Osteoarthritis Outcome Score (KOOS), and Lysholm score. Clinical failure was defined as revision surgery and/or progression to total knee arthroplasty (TKA). A matched-pairs t test was used to analyze differences between the 2 treatment groups, and Kaplan-Meier analysis was used to determine the rates of knee osteoarthritis and progression to TKA.

Results

The majority of patients had a medial meniscal tear (72.8%), whereas the lateral meniscus was torn in 27.2% of cases. Most tears were located in the meniscal root (56.8%), followed by the posterior horn (34.6%) and midbody (8.6%). At final follow-up, all outcome scores were higher in the repair group compared with the meniscectomy group (IKDC, 78.9 ± 13.4 vs 56.0 ± 15.4; KOOS, 86.6 ± 11.9 vs 61.7 ± 16.2; Lysholm, 88.3 ± 13.3 vs 68.7 ± 15.2, respectively; P < .001 for all). Clinical failure was observed in 22% of patients in the repair group.

Conclusion

All clinical outcome scores were higher in the meniscal repair group compared with the matched meniscectomy group at final follow-up. The clinical failure rate of the repair group was 22%. These findings support meniscal repair in selected patients aged ≥60 years.

Meniscal Tear Management Associated with ACL Reconstruction

Meniscal lesions often occur in association with anterior cruciate ligament (ACL) tears at the moment of the injury or, secondarily, as a consequence of knee instability. Both ACL and meniscus lesions are associated with a higher risk of osteoarthritis. Adequate treatment of these lesions reduces the rate of degenerative changes in the affected knee. Meniscal tears should be addressed concomitantly with ACL reconstruction and the treatment must be oriented towards preserving the meniscal tissue anytime this is possible. Several options for approaching a meniscus tear are available. The meniscal suture should always be considered, and, if possible, meniscectomy should be the last choice. “Masterly neglect” is a valuable option in selected cases.

The Prevalence of Tibiofemoral Knee Osteoarthritis Following Arthroscopic Partial Meniscectomy Is Variably Reported in General, and Over Time: A Systematic Review With a Minimum of 5-Year Follow-Up

Purpose

Methods

Results

Conclusions

Level of Evidence

Implantation of autogenous meniscal fragments wrapped with a fascia sheath induces fibrocartilage regeneration in a large meniscal defect in sheep: A histological and biomechanical study

INTRODUCTION

Currently, various studies have been reported to regenerate the meniscus tissue in a large defect after partial meniscectomy using biological or synthetic scaffolds with or without fibrochondrocytes. However, the clinical utility of those treatments has not been established as of yet.

HYPOTHESIS

Purposes of this study were to develop a sheep model to evaluate feasibility of this new surgical strategy to treat the irreparable meniscus injury, and to test the hypothesis that implantation of autogenous meniscal fragments wrapped with a fascia sheath may significantly induce fibrocartilage regeneration in a large meniscal defect in the sheep model.

METHODS AND METHODS

Twenty Suffolk sheep were used. In each animal, an anterior 10-mm width of the right medial meniscus was resected. Then, the animals were divided into the following 2 groups. In Group I, the defect was enveloped with a fascia from the left thigh. In Group II, the resected meniscus fragmented into small pieces was grafted into the defect. Then the defect was enveloped with a fascia. In each group, 5 of 10 sheep were used for histological and biomechanical evaluations, respectively, at 12 weeks after surgery.

RESULTS

In Group I, the defect was incompletely filled with thin fibrous tissues, while fibrocartilage tissues rarely regenerated in the tissue. In Group II, all defects were completely filled with thick fibrocartilage tissues, which were richly stained with the safranin O staining. Both the gross and histological observation score of Group II was significantly (p=0.0005, p=0.0005) greater than that of Group I. Concerning the cross-sectional area of the regenerated tissue, Group II was significantly (p=0.0002) greater than Group I. In the biomechanical evaluation, the maximal load and the linear stiffness of the meniscus-tibia complex were significantly (p=0.0015, p=0.0283) greater in Group II than in Group I.

DISCUSSION

Implantation of autogenous meniscal fragments wrapped with a fascia sheath significantly induces fibrocartilage regeneration into a large meniscal defect in the sheep model.

LEVEL OF EVIDENCE

Not applicable; Controlled Laboratory Study, Experimental in vivo study.

Failed meniscal repair increases the risk for osteoarthritis and poor knee function at an average of 9 years follow-up

PURPOSE

The purpose of this study was to determine the effect of meniscal repair on OA in the knee joint and patient-related outcomes.

METHODS

Three-hundred and sixteen meniscal repairs performed between 1999 and 2011 were analysed. Patient-related outcome measures were assessed through mailed questionnaires including KOOS, Lysholm score and Tegner activity level. Patients answering the questionnaires were encouraged to perform a radiographic evaluation with Rosenberg views, assessed according to Kellgren-Lawrence (KL) classification. The primary endpoint was to determine the effect of meniscal repair on the development of radiographic OA defined as a KL grade 2 or more.

RESULTS

Mean follow-up time was 9.3 years (SD 3.6), 162 (51%) patients answered the questionnaires, and 86 patients completed the X-ray. The odds ratio for OA with a failed meniscus repair was 5.1 (p = 0.007) adjusted for gender and age at time of follow-up. KOOS showed a clinically important difference in the sport and recreation subscale (p = 0.041).

CONCLUSIONS

There was an increased risk for OA in the affected compartment with a failed meniscus fixation. This supports the fact that the meniscus is an important protector of the cartilage in the knee. The meniscus injury affects the long-term health-related quality of life according to KOOS and in light of this study we recommend repair of a torn meniscus whenever possible.

LEVEL OF EVIDENCE

III.

Deep flexion helps to avoid popliteal artery injury during all-inside lateral meniscal repair: A cadaveric study

BACKGROUND

Arthroscopic meniscus repair rarely leads to major complications such as popliteal artery injury. The distance between the suturing device and the popliteal artery, and the risk of popliteal artery injury at different knee flexion angles during all-inside lateral meniscal repair remain unclear.

METHODS

All-inside devices were inserted into 10 human cadaveric knees at the posterior horn of the lateral meniscus through the anterolateral portal at 60°, 90°, and 120° knee flexion; posterior segment of the lateral meniscus through the anterolateral portal at 60°, 90°, and 120°; and anteromedial portal at 90°. Distance and positional relationship between the device and popliteal artery were measured radiographically.

RESULTS

In posterior horn repair through the anterolateral portal, the median distance increased from 5.7 mm at 60° to 9.1 mm at 90° (P = 0.63) and 18.0 mm at 120° (P = 0.02). The device pushed the wire at 60° in three cases, 90° in one case, and 120° in 0 cases. In posterior segment repair through the anterolateral portal, the median distance was 12.6 mm at 60°, 10.4 mm at 90°, and 18.3 mm at 120° (P = 0.08). The median distance at 90° was 18.1 mm through the anteromedial portal, the same as that at 120° through the anterolateral portal (P = 0.43), but greater than that at 90° through the anterolateral portal (P = 0.04). The wire was not pushed in any case.

CONCLUSION

Although all-inside repair of the posterior part of the lateral meniscus through the anterolateral portal is risky, deeper knee flexion reduces the risk of popliteal artery injury.

Mesenchymal stem cells for enhancing biological healing after meniscal injuries

The meniscus is a semilunar fibrocartilage structure that plays important roles in maintaining normal knee biomechanics and function. The roles of the meniscus, including load distribution, force transmission, shock absorption, joint stability, lubrication, and proprioception, have been well established. Injury to the meniscus can disrupt overall joint stability and cause various symptoms including pain, swelling, giving-way, and locking. Unless treated properly, it can lead to early degeneration of the knee joint. Because meniscal injuries remain a significant challenge due to its low intrinsic healing potential, most notably in avascular and aneural inner two-thirds of the area, more efficient repair methods are needed. Mesenchymal stem cells (MSCs) have been investigated for their therapeutic potential in vitro and in vivo. Thus far, the application of MSCs, including bone marrow-derived, synovium-derived, and adipose-derived MSCs, has shown promising results in preclinical studies in different animal models. These preclinical studies could be categorized into intra-articular injection and tissue-engineered construct application according to delivery method. Despite promising results in preclinical studies, there is still a lack of clinical evidence. This review describes the basic knowledge, current treatment, and recent studies regarding the application of MSCs in treating meniscal injuries. Future directions for MSC-based approaches to enhance meniscal healing are suggested.

The Top 50 Most-Cited Knee Arthroscopy Studies

Purpose

To objectively identify the 50 most influential studies in knee arthroscopy and provide an analysis of their key characteristics.

Methods

The Clarivate Analytics Web of Knowledge database was used to gather data and metrics of knee arthroscopy research. The search list was sorted by the number of citations, and articles were included or excluded based on relevance to knee arthroscopy. The information extracted for each article included author name, publication year, country of origin, journal name, article type, and the level of evidence.

Results

For these 50 studies, the total number of citations was calculated to be 12,168, with an average of 243.4 citations per paper. The most-cited article was cited 1,220 times. The 50 studies included in this analysis were published between 1972 and 2013. All 50 articles were published in English and came from 10 different orthopaedic journals. The United States was responsible for the majority of articles (n = 26); however, many other countries were represented. The most prevalent study designs were case series (n = 20).

Conclusions

The 50 most influential articles in knee arthroscopy were cited a total of 12,168 times. The study designs most commonly used were case series and cohort studies. This article serves as a reference to direct orthopaedic practitioners to the 50 most influential studies in knee arthroscopy. We hope that these 50 studies and the analysis we provide help health care professionals efficiently assess consensus, trends, and needs within the field.

Clinical Relevance

This analysis of the 50 most influential studies in knee arthroscopy will provide medical students, residents, fellows, and attending physicians with a comprehensive inventory and citation analysis of the most impactful academic contributions to one of the most important fields within orthopaedic surgery.

Tranexamic Acid Use in Knee and Shoulder Arthroscopy Leads to Improved Outcomes and Fewer Hemarthrosis-Related Complications: A Systematic Review of Level I and II Studies

PURPOSE

To systematically review the literature to compare the efficacy and safety of tranexamic acid (TXA) as a means to minimize hemarthrosis-related complications after arthroscopic procedures of the knee, hip, and shoulder.

METHODS

A systematic review according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was performed by searching PubMed, Cochrane Library, and Embase databases to locate randomized controlled trials comparing the clinical outcomes and postoperative complications of patients undergoing arthroscopy with and without TXA. Search terms used were "tranexamic acid," "arthroscopy," "knee," "hip," and "shoulder." Patients were evaluated based on early (<6 weeks) postoperative signs of hemarthrosis using the Coupens and Yates classification, postoperative complications (myocardial infarction, stroke, venous thromboembolism events), range of motion (ROM), and patient-reported outcome scores (Visual analog scale, Subjective International Knee Documentation Committee, Lysholm, and Tegner activity scores).

RESULTS

Five studies (2 level I and 3 level II) met inclusion criteria, including a total of 299 patients undergoing arthroscopy with TXA and 299 patients without TXA. The average follow-up duration for all patients was 43.9 days. Procedures performed were partial meniscectomy, anterior cruciate ligament reconstruction, and rotator cuff repair. No studies evaluating TXA use in hip arthroscopy were identified. Coupens-Yates hemarthrosis grades significantly improved in the TXA groups across all studies. Three studies found TXA patients to experience significantly less postoperative pain at latest follow-up, 1 study found TXA patients to have significantly better postoperative Lysholm scores, and 1 study found TXA patients to have significantly more ROM at latest follow-up compared with non-TXA patients (P < .05).

CONCLUSION

Patients undergoing arthroscopy, particularly arthroscopic meniscectomy, arthroscopic-assisted anterior cruciate ligament reconstruction, and arthroscopic rotator cuff repair, with TXA can be expected to experience improved outcomes and less hemarthrosis-related complications in the early postoperative period compared with non-TXA patients.

LEVEL OF EVIDENCE

II, systematic review of level I and II studies.

Partial meniscectomy provides the favorable outcomes for symptomatic medial meniscus tear with an intact posterior root

PURPOSE

This study aimed to investigate the long-term outcomes of arthroscopic partial meniscectomy for medial meniscus tear (with intact posterior root) and to analyze the risk factors for treatment failure.

METHODS

The records of 165 patients who underwent partial meniscectomy for medial meniscus tear with intact posterior root with a minimum 5-year follow-up were included. Modified Lysholm score and radiologic outcomes were compared between preoperative and latest follow-up periods. The cumulative Outerbridge grade of the medial compartment was defined as follows: 0-4, low chondral wear; 5-6, intermediate wear; or 7-8, high wear. Kaplan-Meier survival and Cox hazard regression analyses were performed to assess the survivorship after partial meniscectomy. Conversion to total knee replacement arthroplasty, high tibial osteotomy or a Lysholm score of < 65 points indicated treatment failure.

RESULTS

Mean Lysholm score improved from 66.3 ± 14.2 preoperatively to 81.8 ± 17.9 at the latest follow-up (p = 0.001). The postoperative 10-year survival rate of the low chondral wear group [97% (95% confidence interval (CI) 141.7-152.6 months)] was higher than that of the intermediate [83.1% (95% CI 129.6-147.9 months)] and high wear groups [76.1% (95% CI 115.2-135.0 months)]. A 1 mm joint space width narrowing led to a 37.7% increase in the failure rate [B = - 0.473; hazard ratio, 0.623 (95% CI 0.423-0.917); p = 0.016]. The high chondral wear group showed a higher failure rate compared to the low wear group [B = 1.870; hazard ratio, 6.488 (95% CI 0.853-49.333); p = 0.041].

CONCLUSION

Partial meniscectomy offers pain relief and functional improvement for medial meniscus tear with intact posterior root. Preoperative joint space narrowing and higher chondral wear at surgery were significant risk factors of treatment failure. Partial meniscectomy should be considered as an effective treatment for irreparable medial meniscus tear with intact posterior root without joint space narrowing and chondral wear.

LEVEL OF EVIDENCE

Case series, Level IV.

Meniscus repairs in the adolescent population-safe and reliable outcomes: a systematic review

PURPOSE

The purpose of this study was to determine the outcomes of meniscus repair in the adolescent population, including: (1) failure and reoperation rates, (2) clinical and functional results, and (3) activity-related outcomes including return to sport.

METHODS

Two authors independently searched MEDLINE, Cochrane Central Register of Controlled Trials & Cochrane Library, and CINHAL databases for literature related to meniscus repair in an adolescent population according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. No meta-analysis was performed in this qualitative systematic review.

RESULTS

Thirteen studies, including no Level I, one Level II, one Level III, and eleven Level IV studies yielded 466 patients with 503 meniscus repairs. All defined meniscal re-tear as a primary endpoint, with a reported failure rate ranging from 0 to 42% at a follow-up ranging from 22 to 211 months. There were a total of 93 failed repairs. IKDC scores were reported in four studies with a mean improvement ranging from 24 to 42 (P < 0.001). Mean post-operative Lysholm scores were reported in seven studies, ranging from 85 to 96. Additionally, four of those studies provided mean pre-operative Lysholm scores, ranging from 56 to 79, with statistically significant mean score improvements ranging from 17 to 31. Mean post-operative Tegner Activity scores were reported in nine studies, with mean values ranging from 6.2 to 8.

CONCLUSION

This systematic review demonstrates that both subjective and clinical outcomes, including failure rate, Lysholm, IKDC, and Tegner activity scale scores, are good to excellent following meniscal repair in the adolescent population. Further investigations should aim to isolate tear type, location, surgical technique, concomitant procedures, and rehabilitation protocols to overall rate of failure and clinical and functional outcomes.

LEVEL OF EVIDENCE

IV.

Chondral lesions at the medial femoral condyle, meniscal degeneration, anterior cruciate ligament insufficiency, and lateral meniscal tears impair the middle-term results after arthroscopic partial meniscectomy

PURPOSE

The aim of the present study was to analyse which clinical, radiological and arthroscopic findings are able to predict the postoperative outcome after arthroscopic partial meniscectomy. Furthermore, the present study aimed to investigate the postoperative outcome after partial meniscectomy in patients with degenerative meniscal lesions.

METHODS

A total of 91 patients with a follow-up period of 34.7 ± 11.4 months after arthroscopic partial meniscectomy were included in this retrospective study. Clinical, radiological, and arthroscopic data were analysed at the time of follow-up. The multivariable linear regression analysis for postoperative outcome, based on the Western Ontario Meniscal Evaluation Tool (WOMET), included age, gender, body mass index, physical activity, presence of cartilage lesions, leg alignment, grade of radiographic osteoarthritis, location of meniscal lesions, meniscal extrusion, meniscal degeneration, presence of an anterior cruciate ligament tears as well as bone marrow lesions.

RESULTS

WOMET and WOMAC scores showed a significant improvement of 45.0 ± 48.1 points (CI 34.9-55.1; p ≤ 0.0001) and 75.1 ± 69.3 points (CI 60.6-89.6; p = 0.001) within the follow-up period. Multivariable linear regression analysis showed that poor preoperative WOMET scores (p = 0.001), presence of cartilage lesions at the medial femoral condylus (p = 0.001), meniscal degeneration (p = 0.008), the presence of an anterior cruciate ligament lesion (p = 0.005), and lateral meniscal tears (p = 0.039) were associated with worse postoperative outcomes. Patients with femoral bone marrow lesions had better outcome (p = 0.038).

CONCLUSION

Poor preoperative WOMET scores, presence of cartilage lesions at the medial femoral condylus, meniscal degeneration, concomitant anterior cruciate ligament lesions as well as lateral meniscal tears are correlated with worse postoperative outcomes after arthroscopic partial meniscectomy. Patients with femoral bone marrow lesions femoral are more likely to gain benefit from arthroscopic partial meniscectomy in the middle term. Despite justified recent restrictions in indication, arthroscopic partial meniscectomy seems to effectively reduce pain and alleviate symptoms in carefully selected patients with degenerative meniscal tears.

LEVEL OF EVIDENCE

III.

Degenerative medial meniscus posterior root tear and non-root tear do not show differences in joint survival and clinical outcome after partial meniscectomy

PURPOSE

No comparative studies of outcomes between degenerative medial meniscus posterior root tear (MM PRT) and non-root tear (NRT) have been conducted. This study aimed to compare joint survival and clinical outcome between MM PRT and MM NRT after partial meniscectomy with proper control of confounding factors.

METHODS

One hundred and ten patients each in MM PRT and MM NRT groups who underwent arthroscopic partial meniscectomy were retrospectively evaluated through propensity score matching. Joint survival was assessed on the basis of surgical and radiographic failures. Clinical outcomes were assessed using the Lysholm score.

RESULTS

The confounding variables were well balanced between the groups, with standardized mean differences of < 0.2 after propensity score matching. Failures occurred in 30 (27.3%) and 35 patients (31.8%) in the MM PRT group and MM NRT group, respectively. The estimated mean survival times were 12.5 years (95% confidence interval [CI] 11.5-13.5) and 11.7 years (10.7-12.7), respectively. There were no significant differences in the overall survival rate and Lysholm score between the two groups (n.s.).

CONCLUSION

In middle-aged patients with degenerative MM PRT, joint survival and clinical outcome showed comparable results with those with MM NRT after partial meniscectomy. Arthroscopic partial meniscectomy is one of the effective treatments for MM PRT with consideration of various patient factors.

LEVEL OF EVIDENCE

III.

Relationship of alignment in the lower extremity with early degeneration of articular cartilage after resection of the medial meniscus: Quantitative analysis using T2 mapping

The objective of this study was to examine the relationship between cartilage degeneration early after partial medial meniscectomy and abnormal alignment in the lower extremity.The subjects were 34 patients (37 knees) with medial meniscal tear who underwent arthroscopic partial meniscectomy. MRI was performed before and 6 months after surgery. T2 mapping images in sagittal sections of medial femoral condyle were produced and 10 regions of interest were set at intervals of 10° in the articular cartilage in the femur. Subjects with an increase in T2 of ≥6% at a flexion angle of 30° were assigned to the degeneration group. Patient background, hip-knee-ankle (HKA) angle, and total resection of meniscal segments were compared between this group and the other patients to identify factors involved in degeneration of articular cartilage.T2 values 6 months after surgery in 3 ROIs at flexion angles of 30° to 50° were significantly longer than those before surgery. The preoperative HKA angle was significantly higher in the degeneration group. T2 values in articular cartilage of the femoral condyle increased earlier after meniscectomy with abnormal alignment in the lower extremity.Meniscectomy in cases with abnormal alignment may have a risk of early onset of osteoarthritis.Level of evidence: Level IV.

Techniques for In Vivo Measurement of Ligament and Tendon Strain: A Review

The critical clinical and scientific insights achieved through knowledge of in vivo musculoskeletal soft tissue strains has motivated the development of relevant measurement techniques. This review provides a comprehensive summary of the key findings, limitations, and clinical impacts of these techniques to quantify musculoskeletal soft tissue strains during dynamic movements. Current technologies generally leverage three techniques to quantify in vivo strain patterns, including implantable strain sensors, virtual fibre elongation, and ultrasound. (1) Implantable strain sensors enable direct measurements of tissue strains with high accuracy and minimal artefact, but are highly invasive and current designs are not clinically viable. (2) The virtual fibre elongation method tracks the relative displacement of tissue attachments to measure strains in both deep and superficial tissues. However, the associated imaging techniques often require exposure to radiation, limit the activities that can be performed, and only quantify bone-to-bone tissue strains. (3) Ultrasound methods enable safe and non-invasive imaging of soft tissue deformation. However, ultrasound can only image superficial tissues, and measurements are confounded by out-of-plane tissue motion. Finally, all in vivo strain measurement methods are limited in their ability to establish the slack length of musculoskeletal soft tissue structures. Despite the many challenges and limitations of these measurement techniques, knowledge of in vivo soft tissue strain has led to improved clinical treatments for many musculoskeletal pathologies including anterior cruciate ligament reconstruction, Achilles tendon repair, and total knee replacement. This review provides a comprehensive understanding of these measurement techniques and identifies the key features of in vivo strain measurement that can facilitate innovative personalized sports medicine treatment.

Medium-Term Results of Arthroscopic Partial Meniscectomy from a Single High-Volume Center

AIM

Clinical practice is moving away from treating meniscal tears in patients with osteoarthritis unless there are mechanical symptoms. This study assessed the risk of needing further surgery for osteoarthritis in the 5 years following partial meniscectomy in different age groups and different grades of knee osteoarthritis.

METHODS

All partial meniscectomies were performed by the senior author during a 31-month period. Data were collected and analyzed retrospectively using electronic patients' records and imaging database. Patients who had previous arthroscopy, anterior cruciate ligament pathology, discoid meniscus or were less than 34 years old were excluded from the study. Range of follow-up was 3 to 5 years. Osteoarthritis was classified intra-operatively using the Outerbridge classification. Knees that needed further surgical treatment in the form of joint replacement or osteotomy were considered as failures. The population was split into three groups according to their age (35-54, 55-64 and 65+). Survival analysis was calculated using the life table method.

RESULTS

207 knees were included. In the 35-54 age group, patients with no/mild OA had a survival rate of 97.59% and the severe OA group had a survival rate of 73.5%. In the 55-64 age group, these figures were 100% and 73.6%, respectively. In the >65 age group, the survival rates were 100% and 65%, respectively.

CONCLUSION

Our study shows that patients with no/mild OA should be considered for APM. Patient's with meniscal tears and severe OA should be counseled on the outcomes and risks of further surgery after an APM.

There Is No Difference in Radiographic Outcomes After Average 9 Years After Arthroscopic Partial Medial Meniscectomy for Both Posterior Horn Tears and Posterior Horn Root Tears

PURPOSE

To compare the serial changes in radiographic outcomes in terms of the mechanical axis (MA) angle and medial joint space width (JSW) between medial meniscus posterior root tear (MM PRT) and non-root tear (MM NRT) after arthroscopic partial meniscectomy (APM).

METHODS

Patients who underwent APM for degenerative MM PRT or MM NRT from January 1999 to July 2012 were retrospectively reviewed. One hundred ten patients each in the MM PRT group and the MM NRT group, who were matched through propensity score matching (adjusting for confounding factors such as age, sex, body mass index, anatomic axis, cartilage state of the medial compartment, and follow-up period), were included in the study. The MA angle on weightbearing whole-leg radiographs and the medial JSW on weightbearing 45° flexion posteroanterior radiographs were measured to evaluate the radiographic outcomes. The serial changes were compared between radiographs taken before surgery, at postoperative 3 to 5 years, and at postoperative 5 years to the last follow-up. The linear mixed model was used to compare the changes in radiographic outcomes during the follow-up period between groups.

RESULTS

The 2 groups were balanced with standardized mean differences of <0.2 after propensity score matching. Both the MM PRT and NRT groups showed increased varus alignment after surgery. However, there was no significant difference in the change in the MA angle during the follow-up period between groups (P = .182). The medial JSW also showed progression of joint space narrowing after surgery in both groups; however, there was no significant difference in the change in medial JSW during the follow-up period between groups (P = .270).

CONCLUSION

The radiographic outcomes after partial meniscectomy in terms of the MA angle and medial JSW show comparable results between degenerative MM PRT and NRT after proper matching of confounding factors.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Role of Alignment and Osteotomy in Meniscal Injuries

Meniscal injuries are common in patients with varus or valgus malalignment, but consensus is lacking as to when surgery should address the meniscal injury only and when it should be combined with an osteotomy. Several factors need to be evaluated to provide the most appropriate treatment in each case. Here we highlight the most relevant literature on the subject and suggest a rationale for surgical treatment.

Does Tranexamic Acid Reduce Knee Swelling and Improve Early Function Following Arthroscopic Meniscectomy? A Double-Blind Randomized Controlled Trial

BACKGROUND

Arthroscopic meniscectomy often results in rapid recovery and return to preinjury activities; however, postoperative hemarthrosis and swelling can lead to pain, decreased range of motion, and delayed return to work and leisure activities. Tranexamic acid (TXA) is a lysine-based inhibitor of plasminogen to plasmin that has gained popularity in arthroplasty surgery for reducing blood loss and, more recently, in anterior cruciate ligament reconstruction by reducing postoperative hemarthrosis, swelling, and pain while increasing function in the short term.

PURPOSE

To determine whether there is a role for TXA in improving the short-term results of swelling, pain, and function following arthroscopic meniscectomy.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 2.

METHODS

We performed a prospective double-blinded randomized controlled trial in 41 patients undergoing arthroscopic meniscectomy by comparing patients treated with intravenous TXA with those treated with a placebo (normal saline). A single surgeon treated all patients. Following randomization, a dose of 1 g of TXA in 100 mL of normal saline (treatment group) or 100 mL of normal saline (placebo group) was given intravenously at induction prior to tourniquet inflation by the anesthetist. The anesthetist administering the TXA or placebo was not blinded, but all other clinicians involved were. Patients were evaluated by a blinded observer at postoperative days 3, 14, and 30, with the range of motion, swelling, pain levels (visual analog scale), and Lysholm and Tegner knee scores recorded.

RESULTS

Patient demographics were similar in both groups. In the treatment group, there was a nonsignificant improvement in range of motion (P = .056) and swelling (P = .384) at 14 days; however, there was a significant improvement in the Tegner score at 3 days (P = .0064). The complication profile was similar between the groups.

CONCLUSION

The administration of 1 g of intravenous TXA in routine arthroscopic meniscectomy may improve early functional recovery without increased risk. A larger study is required to confirm these results and further evaluate any potential benefit.

REGISTRATION

ACTRN12618001600235 (Australian New Zealand Clinical Trials Registry).

The Natural History of Meniscus Tears

BACKGROUND

In order to determine whether treatments are effective in the treatment of meniscus tears, it is first necessary to understand the natural history of meniscus tears. The purpose of this paper is to review the literature to ascertain the natural history of meniscus tears in children and adolescents.

METHODS

A search of the Pubmed and Embase databases was performed using the search terms "meniscus tears," "natural history of meniscus tears," "knee meniscus," "discoid meniscus," and "natural history of discoid meniscus tears."

RESULTS

A total of 2567 articles on meniscus tears, 28 articles on natural history of meniscus tears, 8065 articles on "menisci," 396 articles on "discoid meniscus," and only 2 on the "natural history of discoid meniscus" were found. After reviewing the titles of these articles and reviewing the abstracts of 237 articles, it was clear that there was little true long-term natural history data of untreated meniscus tears nor whether treating meniscus tears altered the natural history. Twenty-five articles were chosen as there was some mention of natural history in their studies.

CONCLUSIONS

There are few long-term data on untreated meniscal tears or discoid meniscus, or tears in children and adolescents. The literature suggests that there is a higher incidence of chondral injury and subsequent osteoarthritis, but there are many confounding variables which are not controlled for in these relatively short-term papers.

[Treatment of degenerative meniscal lesions : From eminence to evidence-based medicine]

BACKGROUND

The treatment of degenerative meniscal lesions has received increased attention since the publication of several Level 1 studies over the last few years. The following review of literature including the consensus statement given by ESSKA reports on the management of patients with degenerative meniscal lesions.

MATERIAL AND METHODS

The analysis includes the literature of Level 1 to 4 studies and the statement of the consensus group of ESSKA concerning the surgical or conservative management of these patients.

RESULTS

Meniscal lesions cause progression in osteoarthritis. Patients presenting a combination of degenerative meniscal lesion and osteoarthritis show inferior clinical outcome. The average clinical outcome after surgical treatment was 70 points based on the Lysholm score. Level 1 studies show no difference in clinical outcome. However, over 30% of these patients require arthroscopy at the second stage after an interval of 3 to 6 months. Patients presenting a flap tear or complaining about mechanical symptoms show poor outcome after conservative treatment.

DISCUSSION

Level 1 studies have focused on very selected patients. These patients do not represent the daily practice of orthopaedic surgeons. The findings of the level 1 studies should, therefore, not be generalized. According to the consensus statement of ESSKA, the treatment of degenerative meniscal lesions should start with conservative management. In the case of persistent symptoms, surgery should be considered after 3 months. In the case of mechanical symptoms, arthroscopy might be indicated earlier. Arthroscopy in advanced osteoarthritic knees is not indicated due to inferior clinical outcome.

Are Orthopaedic Surgeons Performing Fewer Arthroscopic Partial Meniscectomies in Patients Greater Than 50 Years Old? A National Database Study

PURPOSE

To report the trends in arthroscopic partial meniscectomy (APM) for degenerative meniscal tears in a large private insurance database among patients older than 50 years.

METHODS

The Humana database between 2007 and 2015 was queried for this study. Patients meeting the inclusion criteria with degenerative meniscal tears who underwent APMs were identified by International Classification of Diseases, Ninth Revision codes, followed by Current Procedural Terminology codes. A linear regression analysis was performed with a significance level set at F < 0.05.

RESULTS

A total of 21,759 APMs were performed between 2007 and 2015 in patients older than 50 years. Normalized data for total yearly enrollment showed a significant increase in APMs performed from 2007 to 2010 (R² = 0.986, P = .007). The average percentage increase per year from 2007 to 2010 was 18.59%. However, there was a significant decrease in APMs performed from 2010 to 2015 (R² = 0.748, P = .026). The average percentage decrease per year from 2010 to 2015 was 7.74%. The percentage decrease overall from 2010 to 2015 was 71.68%. No difference in statistical significance was found when age was broken into 5-year age intervals. We found a significant difference in APM based on region (P < .001).

CONCLUSIONS

The rate of APMs in patients older than 50 years increased from 2007 until 2010. Since 2010, the rate of APMs in patients older than 50 years has significantly decreased. These trends are likely multifactorial. Regardless of cause, it appears that the orthopaedic surgery community is performing fewer APMs in this patient population.

LEVEL OF EVIDENCE

Level III, retrospective database epidemiological study.

Effects of Ultra-Purified Alginate Gel Implantation on Meniscal Defects in Rabbits

BACKGROUND

Many tissue-engineered methods for meniscal repair have been studied, but their utility remains unclear.

HYPOTHESIS

Implantation of low-endotoxin, ultra-purified alginate (UPAL) gel without cells could induce fibrocartilage regeneration on meniscal defects in rabbits.

STUDY DESIGN

Controlled laboratory study.

METHODS

Forty-two mature Japanese White rabbits were divided into 2 groups of 21 animals each. In each animal, a cylindrical defect measuring 2 mm in diameter was created with a biopsy punch on the anterior horn of the medial meniscus. In the control group, no treatment was applied on the left medial meniscal defect. In the UPAL gel group, the right medial meniscal defect was injected with the UPAL gel and gelated by a CaCl₂ solution. Samples were evaluated at 3, 6, and 12 weeks postoperatively. For biomechanical evaluation, 6 additional samples from intact animals were used for comparison.

RESULTS

The macroscopic score was significantly greater in the UPAL gel group than in the control group at 3 weeks (mean ± SE: 5.6 ± 0.82 vs 3.4 ± 0.83, P = .010), 6 weeks (5.9 ± 0.72 vs 2.5 ± 0.75, P = .026), and 12 weeks (5.2 ± 1.21 vs 1.0 ± 0.63, P = .020). The histological score was significantly greater in the UPAL group than in the control group at 3 weeks (2.1 ± 0.31 vs 1.2 ± 0.25, P = .029) and 12 weeks (2.2 ± 0.55 vs 0.3 ± 0.21, P = .016). The mean stiffness of the reparative tissue in the UPAL gel group was significantly greater than that in the control group at 6 weeks (24.325 ± 3.920 N/mm vs 8.723 ± 1.190 N/mm, P = .006) and at 12 weeks (27.804 ± 6.169 N/mm vs not applicable [because of rupture]).

CONCLUSION

The UPAL gel enhanced the spontaneous repair of fibrocartilage tissues in a cylindrical meniscal defect in rabbits.

CLINICAL RELEVANCE

These results imply that the acellular UPAL gel may improve the repair of traumatic meniscal injuries.

Outcomes After the Operative Treatment of Bucket-Handle Meniscal Tears in Children and Adolescents

Background:

Bucket-handle meniscal tears (BHMTs), which we define as vertical longitudinal tears of the meniscus with displacement of the torn inner fragment toward the intercondylar notch region, are a well-recognized tear pattern. Optimizing the management of BHMTs in younger patients is important, as preserving meniscal tissue may limit future joint degeneration.

Purpose/Hypothesis:

The purpose of this study was to review the patient demographics, clinical presentation, operative details, outcomes, and risk factors for a reoperation associated with operatively treated BHMTs in a pediatric population. We hypothesized that the repair of BHMTs in adolescents would yield a higher reoperation rate than meniscectomy in our population.

Study Design:

Case-series; Level of evidence, 4.

Methods:

A departmental database was queried to identify all patients 19 years or younger who presented with a BHMT and underwent surgery between October 2002 and February 2013. Clinical, radiological, and surgical data were retrospectively collected, and risk factors for a reoperation and persistent pain were assessed in all patients with longer than or equal to 6 months of follow-up.

Results:

A total of 280 BHMTs were treated arthroscopically by 1 of 8 sports medicine fellowship–trained surgeons. The mean age at surgery was 15.5 ± 2.5 years (range, 2.1-19.2 years), and most patients were male (177/280; 63%). Most injuries occurred during sports (203/248; 82%) and involved the medial meniscus (157/280; 56%). Concurrent anterior cruciate ligament (ACL) surgery was performed in 103 cases (37%). Meniscal repair was performed in 181 cases (65%) and was more common in younger patients (P = .01) and for the lateral meniscus (P < .001). Among 185 (66%) cases with longer than or equal to 6 months of adequate follow-up data (which included 126 meniscal repairs [68%]), a meniscus-related reoperation occurred in 45 (24%) cases. A reoperation related to the original BHMT injury or surgery was more common after meniscal repair than after meniscectomy (40/126 [32%] vs 5/59 [8%], respectively) (P = .001) and less common with concurrent ACL surgery (P = .07), although this was not statistically significant. Among patients injured during sports and with adequate follow-up, all but 1 patient (176/177; 99%) returned to sports; a slower rate of return was seen in those undergoing meniscal repair (P = .002) and concurrent ACL surgery (P < .001). At final follow-up, 170 of 185 patients (92%) were pain free. For the 15 patients with persistent pain at final follow-up, no identifiable risk factors for persistent pain were identified.

Conclusion:

Most BHMTs in younger patients occurred in males and during sports and affected the medial meniscus. Concurrent ACL surgery was indicated in approximately one-third of cases and was associated with a lower reoperation rate and slower return to sports. Two-thirds of patients underwent meniscal repair, over two-thirds of whom did not require a reoperation during the study period, despite the high activity levels in this age group.

Comparative Outcomes of All-Inside Versus Inside-Out Repair of Bucket-Handle Meniscal Tears: A Propensity-Matched Analysis

Background:

There are limited data comparing the outcomes of all-inside versus inside-out meniscal repair techniques.

Purpose:

To assess failure rates and clinical outcomes after the surgical repair of bucket-handle meniscal tears utilizing either an all-inside or inside-out technique.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Patients with bucket-handle meniscal tears undergoing all-inside or inside-out repair at a single institution between 2003 and 2013 were analyzed. A total of 28 mensici repaired utilizing second-generation all-inside suturing devices and 42 menisci repaired using an inside-out technique were eligible for inclusion. Rigorous propensity matching was performed on the basis of age, sex, tear laterality, rim width, and concomitant anterior cruciate ligament reconstruction (ACLR), resulting in a total of 40 patients equally distributed between the 2 repair techniques for comparison. Retear-free survival as well as preoperative and postoperative International Knee Documentation Committee (IKDC) and Tegner scores and physical examination findings were subsequently analyzed.

Results:

Twenty patients who underwent all-inside repair (14 male; mean age, 23.7 ± 6.7 years) were successfully propensity matched to 20 patients who underwent inside-out meniscal repair (15 male; mean age, 22.5 ± 7.6 years), with a mean retear-free follow-up of 4.4 years (range, 2.5-7.4 years). Four (20%) all-inside repairs and 4 (20%) inside-out repairs failed over the course of follow-up (P > .999), with a mean time to failure of 2.7 years (range, 1.3-4.4 years) and 5.0 years (range, 0.8-7.5 years), respectively (P = .25). Increasing patient age trended toward a decreased clinical retear rate, independent of the repair technique (hazard ratio, 0.86; P = .056). There were no significant differences in the Tegner scores, IKDC scores, or range of motion between the groups as a whole or when subcategorizing by age, sex, body mass index, tear complexity, rim width, isolated versus concomitant ACLR, or medial- versus lateral-sided repair. There were no complications in the all-inside group, while there was a 10% rate of minor complications in the inside-out group (P = .49).

Conclusion:

Overall, satisfactory clinical outcomes are achievable at short-term to midterm follow-up with both inside-out and all-inside repair techniques of bucket-handle meniscal tears in rigorously matched patients with similar meniscal tear patterns.

Learning From Failure in Cartilage Repair Surgery: An Analysis of the Mode of Failure of Primary Procedures in Consecutive Cases at a Tertiary Referral Center

Background:

As the number of cartilage restoration procedures is increasing, so is the number of revision procedures. However, there remains limited information on the reasons for failure of primary cartilage restoration procedures.

Purpose:

To determine the common modes of failure in primary cartilage restoration procedures to improve surgical decision making and patient outcomes.

Study Design:

Case series; Level of evidence, 4.

Methods:

Patients who presented for revision after failed cartilage repair surgery were evaluated for factors contributing to failure of the primary procedure. All revision cases performed by a single surgeon at a tertiary center for failed cartilage restoration over a 6-year time frame were identified. In all cases, the medical records, preoperative radiographs, and magnetic resonance imaging scans were reviewed by 2 experienced cartilage surgeons. The cause for failure was categorized as malalignment, meniscal deficiency, graft or biologic failure, or instability. Univariate and descriptive statistics regarding patient demographics, index procedure, lesion location and size, and mechanism of failure were analyzed.

Results:

A total of 59 cases in 53 patients (32 male, 21 female) met the inclusion criteria. The mean patient age at the time of revision was 27.6 years, and the mean body mass index was 28.4 kg/m². Failed index surgical procedures included 35 microfractures (59%), 12 osteochondral allograft transplantations (20%), 10 osteochondral autograft transfers (17%), 2 nonviable osteochondral allografts (3%), and 2 particulated juvenile chondral allografts (3%). The mean lesion size was 4.4 cm². Reasons for failure included 33 cases with untreated malalignment (56%), 16 with graft failure (27%), 11 with untreated meniscal deficiency (19%), and 3 with untreated instability (5%); 4 cases demonstrated multiple reasons for failure.

Conclusion:

The most commonly recognized reason for failure was untreated malalignment. While biologic and graft failures will occur, the majority of failures were attributed to untreated background factors such as malalignment, meniscal deficiency, and instability. The stepwise approach of considering and addressing alignment, meniscal volume, and stability remains essential in cartilage restoration surgery.

Arthroscopic partial meniscectomy in young patients with symptomatic discoid lateral meniscus: an average 10-year follow-up study

INTRODUCTION

The aim of this study is to evaluate mid-to-long-term clinical and radiological outcomes after an arthroscopic partial meniscectomy for symptomatic discoid lateral meniscus (DLM) in young patients and to determine whether degeneration of the residual meniscus and articular cartilage progresses during the follow-up period using magnetic resonance imaging (MRI).

MATERIALS AND METHODS

We retrospectively reviewed patients aged ≤ 40 years at surgery who underwent arthroscopic partial meniscectomy for symptomatic DLM and were followed up for ≥ 5 years. Lysholm knee scores and reoperation rates were assessed as clinical outcomes. Factors that affect clinical outcomes were evaluated. Tapper-Hoover classification and femorotibial angle were used for radiological assessment. The degree of degeneration of articular cartilages and residual meniscus was evaluated using preoperative and follow-up MRIs.

RESULTS

A total of 73 knees (66 patients) were enrolled. The mean follow-up period was 10.0 years. The mean follow-up Lysholm knee score was 84.2 ± 14.5, and the reoperation rate was 32.9%. Follow-up Lysholm knee scores were related to duration of symptoms prior to surgery (β = - 0.129, P = 0.003) and femorotibial angle at the last follow-up (β = 1.362, P = 0.045). On simple radiographs, progression of arthritis of the lateral compartment was observed in 68.5% (49 knees). In MRI analyses, degeneration of the residual meniscus progressed in 52.9% (34 knees) (P < 0.001), and significant changes in modified Yulish scores were observed in both lateral femoral and tibial condyles (P < 0.001, both condyles).

CONCLUSIONS

After an arthroscopic partial meniscectomy for symptomatic DLM, unfavorable clinical outcomes were shown in > 30% of the patients during a mean follow-up of 10.0 years. Clinical outcomes based on the patient-reported outcome measures were related to durations of symptoms prior to surgery and alignment at the last follow-up. In radiological and MRI assessments, progression of degeneration of articular cartilages in the lateral compartments of the knees and residual menisci was observed.

Novel technique for repairing posterior medial meniscus root tears using porcine knees and biomechanical study

Transtibial pullout suture (TPS) repair of posterior medial meniscus root (PMMR) tears was shown to achieve good clinical outcomes. The purpose of this study was to compare biomechanically, a novel technique designed to repair PMMR tears using tendon graft (TG) and conventional TPS repair. Twelve porcine tibiae (n = 6 each) TG group: flexor digitorum profundus tendon was passed through an incision in the root area, created 5 mm postero-medially along the edge of the attachment area. TPS group: a modified Mason-Allen suture was created using no. 2 FiberWire. The tendon grafts and sutures were threaded through the bone tunnel and then fixed to the anterolateral cortex of the tibia. The two groups underwent cyclic loading followed by a load-to-failure test. Displacements of the constructs after 100, 500, and 1000 loading cycles, and the maximum load, stiffness, and elongation at failure were recorded. The TG technique had significantly lower elongation and higher stiffness compared with the TPS. The maximum load of the TG group was significantly lower than that of the TPS group. Failure modes for all specimens were caused by the suture or graft cutting through the meniscus. Lesser elongation and higher stiffness of the constructs in TG technique over those in the standard TPS technique might be beneficial for postoperative biological healing between the meniscus and tibial plateau. However, a slower rehabilitation program might be necessary due to its relatively lower maximum failure load.

MRI characteristics of torn and untorn post-operative menisci

OBJECTIVE

To compare magnetic resonance imaging (MRI) characteristics of torn and untorn post-operative menisci.

METHODS

The study group consisted of 140 patients with 148 partially resected menisci who were evaluated with a repeat knee MRI examination and subsequent repeat arthroscopic knee surgery. Two musculoskeletal radiologists retrospectively assessed the following MRI characteristics of the post-operative meniscus: contour (smooth or irregular), T2 line through the meniscus (no line, intermediate signal line, intermediate-to-high signal line, and high fluid-like signal line), displaced meniscus fragment, and change in signal pattern through the meniscus compared with baseline MRI. Positive predictive values (PPV) and negative predictive values (NPV) were calculated using arthroscopy as the reference standard.

RESULTS

All 36 post-operative menisci with no T2 line were untorn at surgery (100% NPV), whereas 46 of the 79 post-operative menisci with intermediate T2 line, 16 of the 18 post-operative menisci with intermediate-to-high T2 line, and 14 of the 15 post-operative menisci with high T2 line were torn at surgery (58.2%, 88.9%, and 93.3% PPV respectively). Additional MRI characteristics associated with torn post-operative meniscus at surgery were irregular meniscus contour (PPV 85.7%), displaced meniscus fragment (PPV 100%), and change in signal pattern through the meniscus (PPV 99.4%).

CONCLUSIONS

Post-operative menisci with no T2 signal line were untorn at surgery. The most useful MRI characteristics for predicting torn post-operative menisci at surgery were change in signal pattern through the meniscus compared with baseline MRI, and displaced meniscus fragment followed by high T2 line through the meniscus, intermediate-to-high T2 line through the meniscus, and irregular meniscus contour.

Systematic Review of the Long-term Surgical Outcomes of Discoid Lateral Meniscus

PURPOSE

To evaluate the surgical treatment of the discoid lateral meniscus (DLM) with long-term follow-up and to search which factors are related to good clinical or radiological outcomes.

METHODS

Search was performed using a MEDLINE, EMBASE, and Cochrane database, and each of the selected studies was evaluated for methodological quality using a risk of bias (ROB) covering 7 criteria. Clinical and radiological outcomes with more than 5 years of follow-up were evaluated after surgical treatment of DLM. They were analyzed according to the age, follow-up period, kind of surgery, DLM type, and alignment.

RESULTS

Eleven articles (422 DLM cases) were included in the final analysis. Among 7 criteria, 3 criteria showed little ROB in all studies. However, 4 criteria showed some ROB ("Yes" in 63.6% to 81.8%). The minimal follow-up period was 5.5 years (weighted mean follow-up: 9.1 years). Surgical procedures were performed with open or arthroscopic partial central meniscectomy, subtotal meniscectomy, total meniscectomy, or partial meniscectomy with repair. The majority of the studies showed good clinical results. Mild joint space narrowing was reported in the lateral compartment, but none of the knees demonstrated moderate or advanced degenerative changes. Increased age at surgery, longer follow-up period, and subtotal or total meniscectomy could be related to degenerative change. The majority of the complications was osteochondritis dissecans at the lateral femoral condyle (13 cases) and reoperation was performed by osteochondritis dissecans (4 cases), recurrent swelling (2 cases), residual symptom (1 case), stiffness (1 case), and popliteal stenosis (1 case).

CONCLUSIONS

Good clinical results were obtained with surgical treatment of symptomatic DLM. The progression of degenerative change was minimal and none of the knees demonstrated moderate or advanced degenerative changes. Increased age at surgery, longer follow-up period, and subtotal or total meniscectomy were possible risk factors for degenerative changes.

LEVEL OF EVIDENCE

Level IV, systematic review of Level IV studies.

Knee Arthroscopic Surgery in Middle-Aged Patients With Meniscal Symptoms: A 3-Year Follow-up of a Prospective, Randomized Study

BACKGROUND

The optimal treatment for middle-aged patients with knee pain and meniscal lesions has been extensively debated. Most previous studies have revealed only short-term beneficial results of knee arthroscopic surgery. The authors have previously shown a positive benefit of knee arthroscopic surgery and an exercise program after 1 year when compared with an exercise program alone.

PURPOSE

To evaluate if knee arthroscopic surgery combined with an exercise program provided an additional long-term benefit after 3 years compared with an exercise program alone in middle-aged patients with meniscal symptoms.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

Of 179 eligible patients, aged 45 to 64 years, 150 were randomized to (1) a 3-month exercise program (nonsurgery group) or (2) the same as group 1 plus knee arthroscopic surgery within 4 weeks (surgery group). The primary outcome was the change in the Knee Injury and Osteoarthritis Outcome Score (KOOS) subscore of pain between baseline and the 3-year follow-up. Results from the 1-year follow-up have been published previously.

RESULTS

Both treatment groups improved significantly in the KOOS pain subscore at 3 years' follow-up in the intention-to-treat and as-treated analyses ( P < .001). The between-group difference for the change in the KOOS pain subscore between baseline and the 3-year follow-up was no longer statistically significant, neither in the intention-to-treat analysis (7.6 points; 95% CI, -0.6 to 15.9; P = .068) nor in the as-treated analysis (5.3 points; 95% CI, -3.1 to 13.8; P = .216). The factorial analysis of the effect of the intervention and age, onset of pain, and mechanical symptoms indicated that older patients improved more, regardless of treatment, and surgery may be more beneficial for patients without mechanical symptoms (as-treated analysis). The effect of the predictive factors on the KOOS pain subscore was uncertain because of the small sample size in the subgroup analyses.

CONCLUSION

The benefit of knee arthroscopic surgery, seen at 1 year in middle-aged patients with meniscal symptoms, was diminished at 3 years and was no longer statistically significant.

CLINICAL RELEVANCE

Knee arthroscopic surgery may be beneficial for middle-aged patients with meniscal symptoms in addition to an exercise program. Older age and absence of mechanical symptoms should not be contraindications to surgery. Registration: NCT01288768 ( ClinicalTrials.gov identifier).

Hydrogels for precision meniscus tissue engineering: a comprehensive review

The meniscus plays a pivotal role to preserve the knee joint homeostasis. Lesions to the meniscus are frequent, have a reduced ability to heal, and may induce tibiofemoral osteoarthritis. Current reconstructive therapeutic options mainly focus on the treatment of lesions in the peripheral vascularized region. In contrast, few approaches are capable of stimulating repair of damaged meniscal tissue in the central, avascular portion. Tissue engineering approaches are of high interest to repair or replace damaged meniscus tissue in this area. Hydrogel-based biomaterials are of special interest for meniscus repair as its inner part contains relatively high proportions of proteoglycans which are responsible for the viscoelastic compressive properties and hydration grade. Hydrogels exhibiting high water content and providing a specific three-dimensional (3D) microenvironment may be engineered to precisely resemble this topographical composition of the meniscal tissue. Different polymers of both natural and synthetic origins have been manipulated to produce hydrogels hosting relevant cell populations for meniscus regeneration and provide platforms for meniscus tissue replacement. So far, these compounds have been employed to design controlled delivery systems of bioactive molecules involved in meniscal reparative processes or to host genetically modified cells as a means to enhance meniscus repair. This review describes the most recent advances on the use of hydrogels as platforms for precision meniscus tissue engineering.

The Role of Arthroscopic Partial Meniscectomy in the Management of Degenerative Meniscus Tears: A Review of the Recent Literature

BACKGROUND

The use of arthroscopic partial meniscectomy for middle aged to older adults with knee pain is one of the most common surgical procedures with approximately 150,000 knee arthroscopies being carried out in the United Kingdom each year, and about five times that number in the United States. Despite this, the procedure remains controversial. The aim of this paper is to provide a comprehensive review of the role of arthroscopic meniscectomy in patients with degenerative meniscus tears and suggest recommendations for clinical practice.

METHODS

A thorough literature search was performed using available databases, including Pubmed, Medline, EMBASE and the Cochrane Library to cover important randomised control trials surrounding the use of arthroscopic partial meniscectomy.

RESULTS

The majority of randomised control trials suggest that arthroscopic partial meniscectomy is not superior to conservative measures such as exercise programmes. Furthermore, one randomised control trial found that arthroscopic partial meniscectomy was not even superior to sham surgery.

CONCLUSION

There is significant overtreatment of knee pain with arthroscopic partial meniscectomy when alternative, less invasive and less expensive treatment options are equally effective. First-line treatment of degenerative meniscus tears should be non-operative therapy focused on analgesia and physical therapy to provide pain relief as well as improve mechanical function of the knee joint. Arthroscopic partial meniscectomy should be considered as a last resort when extensive exercise programmes and physiotherapy have been tried and failed.

Riboflavin-induced photo-crosslinking of collagen hydrogel and its application in meniscus tissue engineering

A meniscus tear is a common knee injury, but its regeneration remains a clinical challenge. Recently, collagen-based scaffolds have been applied in meniscus tissue engineering. Despite its prevalence, application of natural collagen scaffold in clinical setting is limited due to its extremely low stiffness and rapid degradation. The purpose of the present study was to increase the mechanical properties and delay degradation rate of a collagen-based scaffold by photo-crosslinking using riboflavin (RF) and UV exposure. RF is a biocompatible vitamin B2 that showed minimal cytotoxicity compared to conventionally utilized photo-initiator. Furthermore, collagen photo-crosslinking with RF improved mechanical properties and delayed enzyme-triggered degradation of collagen scaffolds. RF-induced photo-crosslinked collagen scaffolds encapsulated with fibrochondrocytes resulted in reduced scaffold contraction and enhanced gene expression levels for the collagen II and aggrecan. Additionally, hyaluronic acid (HA) incorporation into photo-crosslinked collagen scaffold showed an increase in its retention. Based on these results, we demonstrate that photo-crosslinked collagen-HA hydrogels can be potentially applied in the scaffold-based meniscus tissue engineering.

Comparison of Lateral Closing-Wedge Versus Medial Opening-Wedge High Tibial Osteotomy on Knee Joint Alignment and Kinematics in the ACL-Deficient Knee

BACKGROUND

Lateral closing-wedge (LCW) and medial opening-wedge (MOW) high tibial osteotomies (HTOs) correct varus knee alignment and stabilize the anterior cruciate ligament (ACL)-deficient knee. Tibiofemoral and patellofemoral alignment and kinematics after HTO are not well quantified.

PURPOSE

To compare the effect of LCW and MOW HTO on tibiofemoral and patellofemoral alignment in the ACL-deficient knee.

STUDY DESIGN

Controlled laboratory study.

METHODS

Anterior drawer, Lachman, and pivot-shift tests were performed on cadaveric specimens (N = 16), and anterior tibial translation and tibial rotation were measured for the native and ACL-sectioned knee. The right and left knee of each cadaveric specimen underwent an LCW and MOW HTO, respectively, and stability testing was repeated. All cadavers underwent pre- and postosteotomy computerized tomography with 3-dimensional computer modeling to determine the effect of HTO on posterior tibial slope, as well as tibial and patellofemoral axial plane alignment (tibial axial rotation and patellar axial tilt).

RESULTS

Correction to neutral coronal alignment was obtained with both osteotomy techniques; however, larger posterior tibial slope neutralization was achieved with LCW compared with MOW (mean ± SD, 11° ± 3.8° vs 5° ± 5°). LCW demonstrated a greater decrease in anterior tibial translation (P < .05) during Lachman testing, with translation values approximating those of the native knee, especially for the lateral compartment. A similar decrease in anterior tibial translation with LCW was not found during anterior drawer testing. Anterior tibial translation did not improve for either the Lachman or the anterior drawer test after MOW. Osteotomy type did not affect tibial rotation with pivot shift. Relative to MOW, LCW resulted in greater tibial axial rotation and patellar axial tilt (7.7° ± 4° and 5.6° ± 3.9° [LCW], 2.8° ± 2.3° and 2.4° ± 0.9° [MOW], respectively; P < .05).

CONCLUSION/CLINICAL RELEVANCE

LCW shows more reproducible posterior tibial slope neutralization and decreased anterior tibial translation in ACL deficiency compared with MOW; however, LCW is associated with increased external tibial axial rotation and lateral patellar tilt, which may adversely affect the patellofemoral joint. More work is needed to understand the clinical and functional outcome of these biomechanical findings in the ACL-deficient knee.

Clinical Outcomes After Revision Meniscus Repair

PURPOSE

To (1) report outcomes for patients who underwent revision meniscal repair and (2) define both clinical and surgical risk factors for recurrent failure.

METHODS

The records of all patients who underwent revision meniscal repair between 1997 and 2012 were retrospectively reviewed. Surgical technique of primary and revision meniscus repair was detailed, and tears were characterized by type and location. Clinical examination and International Knee Documentation Committee (IKDC) and Tegner scores were used to determine outcomes after revision meniscus repair. Radiographs were reviewed and graded for degenerative changes. Risk factors for failure were analyzed.

RESULTS

Thirty-four patients (24 male/10 female) with an average age of 22 ± 6 years (range, 14 to 38) were included in this study. Twelve lateral menisci and 22 medial meniscal repairs were revised at mean 25 ± 20 months (range, 2 to 76) after primary repair for 11 simple, 9 bucket-handle, and 14 complex tear patterns. Twenty-one tears occurred in the red-red zone and 13 in the red-white zone. At 72 ± 56-month follow-up (range, 2 to 17 years), 7 (21%) cases had documented failure of revision repairs and underwent subsequent partial meniscectomy. Mean Tegner score for all patients was 6.2 ± 1.5 (range, 3 to 9) and IKDC score was 84.8 ± 13.1 (range, 51.7 to 100) at final follow-up. Affected side joint space on radiographs remained stable from a baseline of 4.26 ± 0.88 mm to a final of 4.01 ± 0.84 mm. Multivariable regression identified younger patient age as an independent risk factor for failed revision meniscal repair (P = .01).

CONCLUSIONS

In this study of select revision meniscus repairs, 79% of patients were pain free, without any mechanical symptoms or additional surgeries at a mean of 6 years after revision repair. Younger patients may be at higher risk of failure of the revision meniscus repair.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Immunoglobulin G Deficiency-Associated Septic Arthritis Identified Following Corticosteroid Injection and Knee Arthroscopy: A Case Report

CASE

We present the case of a patient who had worsening pain following intra-articular knee corticosteroid injection and who subsequently underwent arthroscopic partial meniscectomy with positive intraoperative cultures for Staphylococcus lugdunensis. He was treated with multiple irrigation and debridements, and subsequent work-up yielded a diagnosis of immunoglobulin G (IgG) deficiency. We believe that it is critical to maintain a high index of suspicion for underlying immune deficiency when faced with atypical presentations of infections or atypical bacteria in otherwise healthy patients.

CONCLUSION

Knee arthroscopy for the treatment of meniscal tears is one of the most common procedures performed by orthopaedic surgeons in the United States. Patients with an antibody deficiency may have a limited or reduced immune response when presented with a pathogen foreign to the body. This may place the patient at an increased risk of infection and should be addressed through referral to the appropriate subspecialists when recurrent or atypical infection presents to the orthopaedic surgeon.

Controversial role of arthroscopic meniscectomy of the knee: A review

The role of arthroscopic partial meniscectomy (APM) in reducing pain and improving function in patients with meniscal tears remains controversial. Five recent high-quality randomized controlled trials (RCTs) compared non-operative management of meniscal tears to APM, with four showing no difference and one demonstrating superiority of APM. In this review, we examined the strengths and weaknesses of each of these RCTs, with particular attention to the occurrence of inadvertent biases. We also completed a quantitative analysis that compares treatment successes in each treatment arm, considering crossovers as treatment failures. Our analysis revealed that each study was an excellent attempt to compare APM with non-surgical treatment but suffered from selection, performance, detection, and/or transfer biases that reduce confidence in its conclusions. While the RCT remains the methodological gold standard for establishing treatment efficacy, the use of an RCT design does not in itself ensure internal or external validity. Furthermore, under our alternative analysis of treatment successes, two studies had significantly more treatment successes in the APM arm than the non-operative arm although original intention-to-treat analyses showed no difference between these two groups. Crossovers remain an important problem in surgical trials with no perfect analytical solution. With the studies available at present, no conclusion can be drawn concerning the optimal treatment modality for meniscal tears. Further work that minimizes significant biases and crossovers and incorporates sub-group and cost-benefit analyses may clarify therapeutic indications.

Changes in articular cartilage following arthroscopic partial medial meniscectomy

PURPOSE

To examine degenerative changes in all cartilage surfaces of the knee following arthroscopic partial medial meniscectomy.

METHODS

For this prospective cohort study, 14 patients (five female) with a mean age of 47.9 ± 12.9 years who had undergone isolated arthroscopic partial medial meniscectomy were evaluated. Cartilage-sensitive magnetic resonance imaging (MRI) scans were acquired from the operated knees before the index operations, as well as at 6, 12, and 24 months after surgery. The MRI scans were assessed for the prevalence, severity, and size of cartilage degenerations. The clinical outcome was assessed using the SF-36 physical and mental component score and the International Knee Documentation Committee Knee Evaluation Form and was correlated with radiological findings.

RESULTS

There was a significant increase in the severity of cartilage lesions in the medial tibial plateau (P = 0.019), as well as a trend towards an increase in the lateral tibial plateau. The size of the cartilage lesions increased significantly in the medial femoral condyle (P = 0.005) and lateral femoral condyle (P = 0.029), as well as in the patella (P = 0.019). Functional outcome scores improved significantly throughout the follow-up period. There was no correlation between cartilage wear and functional outcome.

CONCLUSIONS

Arthroscopic partial medial meniscectomy is associated with adverse effects on articular cartilage and may lead to an increase in the severity and size of cartilage lesions. Post-operative cartilage wear predominantly affected the medial compartment and also affected the other compartments of the knee. Strategies to reduce subsequent osteoarthritic changes need to involve all compartments of the knee.

LEVEL OF EVIDENCE

IV.

Which patients are less likely to improve during the first year after arthroscopic partial meniscectomy? A multivariate analysis of 201 patients with prospective follow-up

PURPOSE

To determine which specific factors influence the improvements in function and pain at the first year following arthroscopic partial meniscectomy.

METHODS

Between 2012 and 2013, patients who had arthroscopic partial meniscectomy were included (n = 201) and followed prospectively before surgery and at 12 months. Multivariable stepwise analysis included preoperative variables (age, gender, limb side, height, weight, body mass index, comorbidities, smoking, Tegner activity scale, Lysholm knee score, preceding injury and duration of preoperative symptoms) and arthroscopic findings (degree of cartilage lesions, medial or lateral meniscus involvement, type of meniscal tear and concomitant cruciate tear). The Lysholm clinical score at the last follow-up and the time interval for substantial pain relief was modelled as a function of the above predictor variables.

RESULTS

At the last follow-up, the mean Lysholm score improved by 14.6 points (95 % CI 10.4-18.8, P < 0.001), from 68.0 ± 16.1 to 82.6 ± 19.6 points and 153 (76 %) patients declared they were satisfied to have had the operation. The mean time interval for substantial pain relief was 3.5 ± 1.5 months. Females and patients with lower preoperative Lysholm score were correlated with lower post-operative Lysholm score, while females and patients with lateral meniscal tears (compared to medial meniscal tears) were correlated with longer recovery.

CONCLUSIONS

Arthroscopic partial meniscectomy improved pain and function at the first year post-operatively. Female gender, lateral meniscal tear and less favourable preoperative function were relatively correlated to worse post-operative function and longer rehabilitation time.

LEVEL OF EVIDENCE

IV.