Annual trends in arthroscopic meniscus surgery: Analysis of a national database in Japan

Report on Evolving Indications, Technique, and Outcomes of Novel And Surgical Procedures-NUsurface

PURPOSE OF REVIEW

Meniscectomy alters knee function and known to be associated with an increased incidence of knee arthritis. Several methods and materials have been tried to replicate the function of a meniscus. One is a polycarbonate-urethane synthetic medial meniscus implant labeled as NUsurface. It is a non-anchored implant that is meant to replace the native meniscus. This article is intended to give an overview of the NUsurface implant and the experience to date.

RECENT FINDINGS

The NUsurface implant is not intended to be a substitute for arthroplasty but has indications similar to meniscal allografts. It has had both prospective double armed and single armed prospective studies. Follow up at the 2-year mark has shown the implant can be successful in decreasing patients' pain and improving function. However, the reoperation rate has been high with a little over a 1/3 requiring an additional procedure and 30% requiring implant exchanged. With improved surgical technique and knowledge of contributing anatomic variables, the reoperation rate has been decreased by half. The synthetic medial meniscus implant NUsurface is able to improve the quality of life in select patients that are symptomatic after meniscectomy. The reoperation rate is of concern but it is decreasing as we refine the variables contributing to the high rate.

Halving of the meniscectomy rate and their costs in Italy: A 15-years period analysis

PURPOSE

The purpose of this study was to determine the incidence and hospitalization trends of meniscectomy in Italy from 2001 to 2016. A secondary aim was to investigate the economic burden of the disease on the national healthcare system.

METHODS

Data were extracted from the Italian Ministry of Health's National Hospital Discharge Reports. Diagnoses are coded according to the ICD-9-CM. Meniscectomy was defined by the following main procedure codes: 806, 8026 and 8145. By dividing the number of annual cases by the size of the adult population reported annually by ISTAT, incidence rates were computed.

RESULTS

Overall, 1,454,891 meniscectomies were performed in the study period between 2001 and 2016. The incidence was 178 procedures for every 100,000 Italian inhabitants. The incidence declined from 202 in 2001 to 106 in 2016. Males were the largest portion of patients undergoing surgery (68.2%). The average age of patients was 46.59 ± 15.07. A decreasing trend in length of hospital stay was observed over the study period. The annual average cost per 100,000 inhabitants was EUR 491.219 ± 122.148 with a range from EUR 291,500 ± 79.500 in 2016 to EUR 610,500 ± 166.500 in 2004.

CONCLUSION

In Italy, the number of meniscectomies performed in the adult population has almost halved over the study period. Results of the present study in the Italian population seem to reflect how the clinical evidence basis affects surgical technique selection. The economic burden of meniscectomy is relevant in Italy with an estimated expenditure from EUR 181.861.375 to 318.257.406 between 2001 and 2016.

LEVEL OF EVIDENCE

Level III.

Synthetic medial meniscus implant demonstrates high reoperation rates: Patients who retain implant or require implant exchange show improvement in post meniscectomy knee pain and clinical function

PURPOSE

To evaluate the clinical outcomes in the use of a synthetic medial meniscus implant in patients symptomatic after medial meniscectomy and not responsive to nonoperative treatment.

METHODS

This single-arm, multicenter, prospective study enrolled subjects between ages 30 and 75 with postmeniscectomy pain. Changes from baseline to 24 months were measured in the pain subscale of the knee injury and osteoarthritis outcome score (KOOS) and in KOOS overall (average of all 5 subscales) in patients that had received a medial meniscus implant. Success was a 20-point improvement at 24 months, and reoperation rates and implant failures were recorded. Visual Analog Scale, International Knee Documentation Committee, and Western Ontario Meniscal Evaluation Tool scores were also measured.

RESULTS

Of the 115 treated patients, 3 (2.6%) were either lost to follow-up or missed the 24-month visit, 48 (43%) patients had at least 1 subsequent surgery, and 12 (10.7%) had the implant permanently removed. Of the remaining 100 patients, the mean KOOS pain improved 28.4 points at 24 months (P < .001), and the mean KOOS overall improved 28.3 points (P < .001). Of the subjects, 76% had mean scores for KOOS pain above the minimal clinically important difference threshold, and 72% of subjects met or exceeded this threshold for KOOS overall. There were 29 patients (25.9%) who underwent implant exchange. The 24-month clinical outcomes were similar between subjects who had an implant exchange and patients who did not have any subsequent implant procedure (P < .2).

CONCLUSIONS

The synthetic medial meniscus implant shows high reoperation and failure rates. Patients who retained the implant or required implant exchange showed improved pain and function.

Meniscal Allograft Transplantation Concomitant With Cartilage Repair for Symptomatic Lateral Meniscus-Deficient Knees With Over Two Years of Follow-up

Background and objective The treatment for symptomatic meniscus-deficient knees with cartilage defects remains challenging on account of insufficient meniscal substitutes. One solution for this might involve combining meniscal allograft transplantation (MAT) and cartilage repair. In this study, we aimed to analyze the effectiveness and safety of MAT concomitant with cartilage repair for symptomatic lateral meniscus-deficient knees in a setting with limited availability of meniscal transplants in Japan. Methods Nine patients who underwent MAT concomitant with osteochondral transplantation (five) and/or autologous chondrocyte implantations (seven) were followed up for at least two years (mean: 51.2 months, range: 24-84 months). Their demographic data and other characteristics were as follows - mean age: 51.7 years, range: 36-67 years; men/women: 4/5; cause: trauma/discoid meniscus: 8/1; cartilage defect size: mean: 6.7 cm2/knee, range: 1.0-11.3. The effectiveness and safety were evaluated clinically by using the Lysholm Knee Scoring Scale (LKSS) and Japanese Orthopaedic Association (JOA) knee score, physical examination, X-rays, and MRI preoperatively and at one, 12, and 24 months after the implantation. Differences between the variables were analyzed using the Friedman test and Scheffe's multiple comparisons. Results The median LKSS and JOA scores significantly improved from 70 points (range: 21-80) and 35 (25-45) preoperatively to 86.5 (65-98) and 87.5 (80-95) at 24 months after surgery, respectively (p<0.001, p=0.0013). The range of motion (ROM), femorotibial angle, and the lateral joint space showed no significant changes. However, lateral meniscal extrusions (LMEs) increased by 3.0 mm (range: 0-6.3 mm) at one month postoperatively and remained unchanged until two years postoperatively. Treatment failure occurred in one case, which was revised by total knee arthroplasty (TKA) at 18 months postoperatively. Additional surgeries were needed in some cases: lateral meniscal tear (three cases), contracture (two cases), and patellar instability (one case). However, neither infection nor allergic reaction was observed in the blood exams. Conclusions Although MAT concomitant with cartilage repair showed good clinical outcomes, half of the cases needed additional surgeries. Based on our findings, this technique should be adopted only in select cases and performed by a handful of highly experienced surgeons.

Insufficient restoration of meniscal extrusion by transtibial pullout repair for medial meniscus posterior root tears

PURPOSE

The long-term changes in the dynamics of the medial meniscus after transtibial pullout repair for medial meniscus posterior root tears (MMPRTs) are not completely understood. Thus, the aim of this study was to investigate the effects of transtibial pullout repair on MMPRTs and whether the effects would be sustained.

METHODS

Nineteen knees with MMPRTs that were treated by trans-tibial pullout repair were enrolled in this study. Medial meniscus extrusion (MME) was measured by ultrasonography during knee extension (no weight-bearing with the knee at 0° extension: NW0°) and 90° flexion (no weight-bearing with the knee at 90° flexion: NW90°) with the patient in the supine position and with full weight-bearing (FW0°) preoperatively and at 3 and 12 months postoperatively. The clinical outcomes were assessed using the Knee Injury and Osteoarthritis Outcome Score, Lysholm score, and International Knee Documentation Committee score.

RESULTS

The difference in MME with NW0° was not statistically significant between the preoperative (3.4 ± 1.0 mm) and 12-month postoperative (3.7 ± 0.6 mm) time points. The MME with NW90° at 3 (2.1 ± 0.7 mm) and 12 months (2.9 ± 0.6 mm) postoperatively were significantly lower than the preoperative values (3.4 ± 0.8 mm) (P < 0.05). However, the value significantly increased from 3 to 12 months postoperatively (P < 0.05). The MME with FW0° at 12 months postoperatively (4.3 ± 0.6 mm) was significantly larger than that at pre-operatively (3.6 ± 0.9 mm) (P < 0.05). All the patients' clinical conditions were significantly improved at 12 months postoperatively when compared to their preoperative clinical conditions.

CONCLUSION

Surgery did not reduce the extrusion in the no weight-bearing and weight-bearing positions at knee extension, and these values increased in the postoperative period. In addition, while the surgery reduced the extrusion in the knee flexion position, the restoration achieved by the surgery was not sustained in the long term.

LEVEL OF EVIDENCE

Level IV.

The Top 50 Most Cited Publications in Meniscus Research

Injuries to the menisci of the knee are common in orthopedic sports medicine. Bibliometric studies can identify the core literature on a topic and help further our collective knowledge for both clinical and educational purposes. The purpose of the current study was to (1) identify and describe the 50 most cited articles in meniscus research over an 80-year time period to capture a wide range of influential articles and (2) identify the "citation classics" and milestone articles related to the meniscus of the knee. The Science Citation Index Expanded subsection of the Web of Science Core Collection was systematically searched for the 50 most cited meniscus articles. Data pertaining to bibliometric and publication characteristics were extracted and reported using descriptive statistics. The top 50 articles were published between the years 1941 and 2014 and collectively cited 13,152 times. The median (interquartile [IQR]) number of total citations per article was 203.5 (167.0-261.8), while the median citation rate was 9.6 (7.4-13.9) citations per year. The most cited article was "Knee joint changes after meniscectomy," published in 1948. The article with the highest citation rate of 78.4 citations per year was "The long-term consequence of anterior cruciate ligaments and meniscus injuries - osteoarthritis," published in 2007. The majority of articles were clinical outcome studies (n = 28, 56%). The top 50 most cited meniscus articles represent a compilation of highly influential articles which may augment reading curriculums and provide a strong knowledge base for orthopaedic surgery residents and fellows. The decade with the most articles was the 2000s, representing a recent acceleration in meniscus-based research. This is a level IV, cross-sectional study.

Has Arthroscopic Meniscectomy Use Changed in Response to the Evidence? A Large-database Study From Spain

BACKGROUND

Several randomized clinical trials on the treatment of meniscal tears have shown that surgery is not superior to nonoperative treatment in middle-aged and older adults. However, clinical practice has not changed consistently worldwide in response to this evidence, and arthroscopic meniscectomy remains one of the most frequently performed operations.

QUESTIONS/PURPOSES

(1) How has the use of arthroscopic meniscectomy changed in Spain between 2003 and 2018, particularly in middle-aged (35 to 59 years) and older patients (over 60 years) relative to younger patients? (2) How have surgical volumes changed across different healthcare areas in the same health system? (3) How has the proportion of outpatient versus inpatient arthroscopic procedures changed over time?

METHODS

Data on all 420,228 arthroscopic meniscectomies performed in Spain between 2003 and 2018 were obtained through the Atlas of Variations in Medical Practice project (these years were chosen because data in that atlas for 2002 and 2019 were incomplete). This database has been promoted by the Spanish Health Ministry since 2002, and it collects basic information on all admissions to public and public-private partnership hospitals. The Spanish population of 2003 was used to calculate age- and sex-standardized rates of interventions per 10,000 inhabitants and year. To assess the change in standardized rates among the age groups over the study period, a linear regression analysis was used. Standard small-area variation statistics were used to analyze variation among healthcare areas. Data on outpatient surgery and length of stay for inpatient procedures were also included.

RESULTS

The standardized rate of arthroscopic meniscectomy in Spain in 2003 was 4.8 procedures per 10,000 population (95% CI 3.9 to 5.6), while in 2018, there were 6.3 procedures per 10,000 population (95% CI 5.4 to 7.3), which represents an increase of 33%. Standardized rates increased slightly in the age group < 35 years (0.06 interventions per 10,000 inhabitants per year [95% CI 0.05 to 0.08]), whereas they increased more markedly in the age groups of 35 to 59 years (0.14 interventions per 10,000 inhabitants per year [95% CI 0.11 to 0.17]) and in those 60 years and older (0.13 interventions per 10,000 inhabitants per year [95% CI 0.09 to 0.17]). The variability among healthcare areas in the meniscectomy rate progressively decreased from 2003 to 2018. In 2003, 32% (6544 of 20,384) of knee arthroscopies were performed on an outpatient basis, while in 2018, these accounted for 67% (19,573 of 29,430).

CONCLUSION

We observed a progressive increase in arthroscopic meniscectomies in Spain; this procedure was more prevalent in older patients presumed to have degenerative pathologic findings. This increase occurred despite increasing high-level evidence of a lack of the additional benefit of meniscectomy over other less-invasive treatments in middle-aged and older people. Our study highlights the need for action in health systems with the use of financial, regulatory, or incentive strategies to reduce the use of low-value procedures, as well as interventions to disseminate the available evidence to clinicians and patients. Research is needed to identify the barriers that are preventing the reversal of interventions that high-quality evidence shows are ineffective.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Lateral collagen meniscus implant (CMI): techniques and outcomes-a narrative review

The menisci increase the stability of the tibio-femoral joint, distribute axial load, absorb shock, and provide nutrition and lubrification to the knee articular cartilage. Therefore, is it clear the importance of the meniscus on the overall knee function and the need to preserve it during arthroscopic surgery. However, according to many registry databases, meniscectomy is still the most performed meniscus surgery. In a percentage of patients, knee pain and swelling, as well as bone edema on the tibial plateau, could follow meniscus resection; this constellation of symptoms is known as "post-meniscectomy syndrome". If this syndrome is not promptly managed, a rapid worsening of the symptoms and develop of knee osteoarthritis could be expected. While dealing with such condition, the clinician must perform first an accurate clinical examination and a full radiological evaluation. If the patient is candidate for surgery, the replacement of the resected tissue should be performed: a meniscus allograft should be implanted in case of previous total meniscectomy or a meniscus scaffold if the patients has an history of a previous partial resection. The present article represents a comprehensive review of the literature and aims to discuss basic science, preoperative planning and evaluation, indication, surgical technique, and outcomes of the lateral collagen meniscus implant (CMI), a biologic scaffold aimed at replacing partial meniscal defects.

Meniscus repair with simultaneous anterior cruciate ligament reconstruction: Clinical outcomes, failure rates and subsequent processing

PURPOSE

To retrospectively analyze the clinical outcomes of meniscus repair with simultaneous anterior cruciate ligament (ACL) reconstruction and explore the causes of failure of meniscus repair.

METHODS

From May 2013 to July 2018, the clinical data of 165 patients who were treated with meniscus surgery and simultaneous ACL reconstruction, including 69 cases of meniscus repair (repair group) and 96 cases of partial meniscectomy (partial meniscectomy group) were retrospectively analyzed. The exclusion criteria were as follows: (1) ACL rupture associated with fracture, collateral ligament injury, or complex ligament injury; (2) a history of knee surgery; or (3) a significant degree of osteoarthritis. The 69 patients in the repair group were divided into the non-failure group (62 cases) and the failure group (7 cases) depending on the repair effect. Postoperative outcomes of the repair group and the partial meniscectomy group were compared. General conditions and postoperative outcomes of the failure group and the non-failure group were compared. During the median follow-up period of 28 months (range, 4 - 65 months) after the second arthroscopy, postoperative outcomes of seven patients in the failure group were summarized. SPSS 25.0 statistical software was used for statistical analysis. A p value less than 0.05 was considered statistically significant.

RESULTS

Seven patients in the failure group who underwent the second arthroscopy were followed up for (30 ± 17.4) months and their postoperative outcomes were summarized. Compared with the partial meniscectomy group, the International Knee Documentation Committee scores of patients in the repair group improved significantly (p = 0.031). Compared with the non-failure group, more patients in the failure group were younger than 24 years (p = 0.030). The median follow-up period was 39.5 months. All patients recovered well after subsequent partial meniscectomy and relieved clinical symptoms. Visual analog scale scores decreased significantly (p = 0.026), and the International Knee Documentation Committee and Lysholm scores improved significantly (p = 0.046 for both).

CONCLUSION

The failure rate of meniscus repair in this study was 10.1% (7/69), all of which were medial meniscus tears. However, the surgical outcomes of ACL reconstruction were not affected, and there might be a role for graft protection. Therefore, meniscus retears can be successful treated by performing subsequent partial meniscectomy in patients with repair failure.

No decrease in incidence of arthroscopic meniscectomy in a Canadian province

PURPOSE

Arthroscopic meniscectomy (APM) is the most common procedure in orthopedic surgery, despite increasing evidence questioning its benefit over conservative management for treatment of degenerative meniscal tears. The purpose of this study is to determine the epidemiology and trends of APM in Saskatchewan, a Canadian province, over a 20 year period.

METHODS

Physician billing codes were used to identify patients who underwent APM in Saskatchewan between January 1, 1998 and December 31, 2017. Records were obtained from eHealth Saskatchewan, a provincial health database. Data was analyzed for overall incidence and age-specific trends of APM.

RESULTS

A total of 35,099 APMs were performed during the study period. The population of Saskatchewan ranged from 992,314 to 1,150,782 (median 1,017,368) during this time interval, with 81 orthopedic surgeons performing APM. Overall incidence rate of APM did not change significantly over time. No decrease was observed in patients presumed to have degenerative tears (≥ 50 years). The number of meniscectomies in patients ≥ 50 years was significantly greater during the second decade of study compared to the first (OR 1.48, p < 0.01). Conversely, the increase in incidence rate among older patients was not statistically significant (R² = 0.125, n.s.).

CONCLUSION

Overall incidence rate of APM in Saskatchewan has not decreased during the last 20 years. Furthermore, APM frequency increased over time for individuals ≥ 50 years. Several regional factors may have contributed to these findings, including the large proportion of Saskatchewan residents engaged in physically demanding work and barriers to accessing physiotherapy services. Given recent evidence disputing the benefit of APM over conservative measures, this study highlights the need for improved dissemination of evidence, as well as the importance of an individualized treatment plan to address patient-specific factors.

LEVEL OF EVIDENCE

Level IV.

Lateral Meniscal Tears in Young Patients: A Comparison of Meniscectomy and Surgical Repair

Background:

Meniscal tears are common in active patients, but treatment trends and surgical outcomes in young patients with lateral meniscal tears are lacking.

Purpose:

To evaluate treatment trends, outcomes, and failure rates in young patients with lateral meniscal tears.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Patients aged ≤25 years treated surgically for isolated lateral meniscal tears from 2001 to 2017 were identified. Treatment trends were compared over time. International Knee Documentation Committee (IKDC) scores and failure rates were compared by treatment modality (meniscectomy vs meniscal repair). Failure was defined as reoperation, symptomatic osteoarthritis, or a severely abnormal IKDC score. Univariate regression analyses were performed to predict failure and IKDC scores based on treatment, type and location of tear, or extent of meniscectomy.

Results:

Included were 217 patients (226 knees) with a mean age of 17.4 years (range, 7-25 years); of these patients, 144 knees (64%) were treated with meniscectomy and 82 knees (36%) with meniscal repair. Treatment with repair increased over time compared with meniscectomy (P < .001). At a minimum 2-year follow-up (mean, 6.1 ± 3.9 years), 107 patients (110 knees) had IKDC scores, and analysis indicated that although scores in both groups improved from pre- to postoperatively (repair: from 69.5 ± 13.3 to 97.4 ± 4.3; meniscectomy: from 75.7 ± 9.0 to 97.3 ± 3.9; P < .001 for both), improvement in IKDC score was greater after repair (27.9 ± 13.9) versus meniscectomy (21.6 ± 9.4) (P = .005). Included in the failure analysis were 184 patients (192 knees) at a mean follow-up of 8.4 ± 4.4 years. The rates of reoperation, symptomatic osteoarthritis, and failure were not significantly different between the meniscectomy and repair groups.

Conclusion:

An increase was seen in the rate of isolated lateral meniscal tear repair in young patients. IKDC score improvement was greater after repair than meniscectomy, although postoperative IKDC scores were similar. Symptomatic arthritis, reoperation, and failure rates were similar between groups; however, there was a trend for increased arthritis symptoms in patients treated with meniscectomy, especially total meniscectomy. Treatment modality, type and location of tear, and amount of meniscus removed were not predictive of final IKDC scores or failure.

Minimum 10-Year Clinical Outcome of Lateral Collagen Meniscal Implants for the Replacement of Partial Lateral Meniscal Defects: Further Results From a Prospective Multicenter Study

Background:

The collagen meniscal implant (CMI) is a biologic scaffold aimed at replacing partial meniscal defects. The long-term results of lateral meniscal replacement have never been investigated.

Purpose:

To document the clinical outcomes and failures of lateral CMI implantation for partial lateral meniscal defect at a minimum 10-year follow-up.

Study Design:

Case series; Level of evidence, 4,

Methods:

This study included 24 consecutive patients who underwent lateral CMI implantation for partial lateral meniscal defects between April 2006 and September 2009 and who were part of a previous study with a 2-year follow-up. Outcome measures at the latest follow-up included the Lysholm score, Knee injury and Osteoarthritis Outcome Score, visual analog scale (VAS) for pain, Tegner activity level, and EuroQol 5-Dimensions score. Data regarding complications and failures were collected, and patients were asked about their satisfaction with the procedure.

Results:

Included in the final analysis were 19 patients (16 male, 3 female) with a mean age at surgery of 37.1 ± 12.6 years and a mean follow-up of 12.4 ± 1.5 years (range, 10-14 years). Five failures (26%) were reported: 1 CMI removal because of implant breakage and 4 joint replacements (2 unicompartmental knee arthroplasties and 2 total knee arthroplasties). The implant survival rate was 96% at 2 years, 85% at 5 years, 85% at 10 years, 77% at 12 years, and 64% at 14 years. Lysholm scores at the final follow-up were rated as “excellent” in 36% (5 of 14 nonfailures), “good” in 43% (6 of 14), and “fair” in 21% (3 of 14). The VAS score was 3.1 ± 3.1, with only 16% (3 of 19 patients) reporting that they were pain-free; the median Tegner score was 3 (interquartile range, 2-5). All clinical scores decreased from the 2-year follow-up; however, with the exception of the Tegner score, they remained significantly higher compared with the preoperative status. Overall, 79% of patients were willing to undergo the same procedure.

Conclusion:

Lateral CMI implantation for partial lateral meniscal defects provided good long-term results, with a 10-year survival rate of 85% and a 14-year survival rate of 64%. At the final follow-up, 58% of the patients had “good” or “excellent” Lysholm scores. However, there was a general decrease in outcome scores between the short- and the long-term follow-up.

The Patient Acceptable Symptomatic State in Primary Anterior Cruciate Ligament Reconstruction: Predictors of Achievement

PURPOSE

To identify thresholds for patient acceptable symptomatic state (PASS) achievement in a cohort of primary anterior cruciate ligament reconstruction (ACLR) recipients, and to identify factors predictive of PASS achievement.

METHODS

A prospective clinical registry was queried for primary ACLR patients from January 2014 to April 2017 with serial patient-reported outcome measure (PROM) completion at 6, 12, and 24 months. Exclusion criteria included significant concomitant procedures. Knee-based PROMs included the International Knee Documentation Committee (IKDC) score and Knee Injury and Osteoarthritis Outcome Score (KOOS) subscores. PASS threshold values were calculated using receiver operating characteristic (ROC) curves with area under the curve (AUC) analysis. A stepwise multivariate regression identified preoperative and operative predictors of PASS achievement.

RESULTS

A total of 144 primary ACLR patients (30.86 ± 12.78 years, body mass index 25.51 ± 4.64, 41.0% male) were included in the analysis. PASS threshold values were established using ROC curve analysis, all of which exceeded 0.7 on AUC analysis (0.742 to 0.911). Factors impacting odds of PASS achievement in the ACLR cohort included preoperative exercises (odds ratio [OR] 2.95 to 4.74, P = .003 to .038), worker's compensation status (OR 0.25 to 0.28, P = .014 to .033), preoperative scores (OR 1.03 to 1.07, P = .005 to <.001), iliotibial band tenodesis (OR 11.08, P = .010), and anteromedial approach (OR 18.03 to 37.05, P < .001).

CONCLUSION

Factors predictive of PASS achievement in recipients of primary ACLR include functional status (e.g., preoperative exercise, preoperative KOOS Sport/Recreation score), worker's compensation status, technique (e.g., anteromedial) and preoperative PROMs. The results of our study are important in better informing shared decision-making models and improving evidence-based guidelines to optimize patient outcomes.

Type of bone graft and primary diagnosis were associated with nosocomial surgical site infection after high tibial osteotomy: analysis of a national database

PURPOSE

Although several small-scale studies have reported risk factors for surgical site infection (SSI) after high tibial osteotomy (HTO), no study has collectively analysed risk factors in a large cohort. The present study aimed to clarify the risk factors for SSI after HTO using a national database.

METHODS

Data of inpatients who underwent HTO from 2010 to 2017 were obtained from the Diagnosis Procedure Combination database in Japan. Outcome measures were the incidence of SSI and deep SSI after HTO. Associations between SSI and patient data were examined with multivariable logistic regression analysis.

RESULTS

Among 12,853 patients who underwent HTO, 195 developed SSI (1.52%) and 50 developed deep SSI (0.39%). Univariate analysis showed that male sex, smoking, and longer anaesthesia duration were associated with higher incidences of SSI, whereas a primary diagnosis of osteonecrosis and use of natural bone grafts were associated with lower incidences. In multivariable analysis, SSI was positively associated with male sex, anaesthesia duration longer than 210 min (vs. 150-210 min), and use of artificial bone graft (vs. natural bone graft). SSI was negatively associated with age ≤ 49 years (vs. 50-59 years) and a primary diagnosis of osteonecrosis (vs. osteoarthritis).

CONCLUSION

The present study revealed novel risk factors for SSI after HTO that previous studies have failed to find, including use of artificial bone graft and longer anaesthesia duration; primary diagnosis of osteonecrosis and younger age were novel protective factors. These findings will help surgeons assess risks of SSI after HTO in individual patients.

LEVEL OF EVIDENCE

III.

Hypermobile Anterior Horn of the Lateral Meniscus: A Case Report and Literature Review

Hypermobile meniscus is known as one of the causes of knee pain and locking or limitation of the range of motion during knee flexion, even when there is no evidence of meniscus tear on magnetic resonance imaging (MRI). Most such cases show excessive hypermobility of the posterior part of the lateral meniscus. This case report presented a rare case of a hypermobile anterior horn of the lateral meniscus. An 18-year-old woman visited our hospital for left knee pain without trauma. Her physical examination showed a limited range of motion and tenderness in the lateral joint space. However, her MRI did not show any abnormalities. After conservative treatment failed, we performed arthroscopic surgery. The arthroscopic evaluation showed no meniscus and no other intraarticular injury. However, the anterior horn of the lateral meniscus was easily translated beyond the lateral condyle by using a probe. Thus, hypermobile anterior horn of the lateral meniscus was diagnosed. The meniscus was stabilized by the outside-in technique. Immediately after surgery, the catching symptom and pain were alleviated. After three-and-a-half months, she returned to work. The Lysholm score improved from 55, preoperatively, to 100, 1-year postoperatively. In conclusion, careful arthroscopic evaluation is essential for the diagnosis of a hypermobile anterior horn of the lateral meniscus. Arthroscopic meniscus stabilization provides a good outcome for hypermobile meniscus.

Medial and lateral meniscus have a different role in kinematics of the ACL-deficient knee: a systematic review

Importance

Meniscal tears are frequently associated with anterior cruciate ligament (ACL) injury and the correct management of this kind of lesion during ACL-reconstruction procedure is critical for the restoration of knee kinematics. Although the importance of meniscus in knee biomechanics is generally accepted, the influence of medial and lateral meniscus in stability of ACL-deficient knee is still unclear.

Objective

The aim of this study was to review literature, which analysed effects in cadaveric specimens of meniscal tear and meniscectomy of medial and lateral meniscus on laxity in the ACL-deficient knee.

Evidence review

Authors performed a systematic search for cadaveric studies analysing the effect of medial and lateral meniscus tears or resection on kinematics of ACL-deficient knee. Extracted data included year of publications, number of human cadaver knee specimens, description of apparatus testing and instrumented kinematic evaluation, testing protocol and results.

Findings

Authors identified 18 studies that met inclusion and exclusion criteria of current review. The major finding of the review was that the works included reported a difference role of medial and lateral meniscus in restraining ACL-deficient knee laxity. Medial meniscus tear or resection resulted in a significant increase of anterior tibial displacement. Lateral meniscus lesions or meniscectomy on the other hand significantly increased rotation and translation under a coupled valgus stress and internal-rotation torque/pivot shift test.

Conclusions

Medial and lateral meniscus have a different role in stabilising the ACL-deficient knee: while the medial meniscus functions as a critical secondary stabilisers of anterior tibial translation under an anterior/posterior load, lateral meniscus appears to be a more important restraint of rotational and dynamic laxity.

Level of evidence

Level IV, systematic review of level I–IV studies.

National Trends of Meniscectomy and Meniscus Repair in Korea

BACKGROUND

Meniscus surgeries are frequently performed in orthopaedics. However, their current status is not well known in many countries, including Korea. This study aimed to investigate the national trends of meniscus surgery in Korea.

METHODS

Information from the national database was acquired through the Korean Health Insurance Review and Assessment Service from 2010 to 2017. All cases coded as meniscectomy or meniscus repair were included. The total number and incidence of cases of meniscus surgery per 100,000 persons were determined, and the results were stratified by age and gender. The meniscus repair ratio for the total number of meniscus surgeries was evaluated.

RESULTS

The total number and incidence of meniscectomy cases were 65,752 and 137, respectively, in 2010, which increased to 74,088 and 154, respectively, in 2017. The number of meniscectomies increased by 12.67% in 8 years. The total number and incidence of meniscus repair cases were 9,055 and 18, respectively, in 2010, which increased to 14,947 and 31 in 2017. The number of meniscus repairs increased by 65.04%. The meniscus repair ratio was 12.1% in 2010, which increased to 16.8% in 2017. The highest peak was noted for patients who underwent meniscus surgeries in their 50s and 60s. Meniscectomy was performed more frequently in women (57%) than in men (43%), whereas repair was performed more frequently in men (54%) than in women (46%) over the study period.

CONCLUSION

The total number and incidence of meniscus surgeries increased from 2010 to 2017; the number and incidence of meniscus repair procedures increased more rapidly than those of meniscectomy, with the peak treatment age for both surgeries being in the 50s and 60s. The current study will contribute to understanding the epidemiology of meniscus surgery, its prevention, and cost-saving measures in Korea.

Complex Tears, Extrusion, and Larger Excision Are Prognostic Factors for Worse Outcomes 1 and 2 Years After Arthroscopic Partial Meniscectomy for Degenerative Meniscal Tears: A Secondary Explorative Study of the Surgically Treated Group From the Odense-Oslo Meniscectomy Versus Exercise (OMEX) Trial

BACKGROUND

Few studies have examined morphological findings from preoperative magnetic resonance imaging (MRI) and arthroscopic findings as prognostic factors for outcomes 1 and 2 years after arthroscopic partial meniscectomy (APM).

PURPOSE/HYPOTHESIS

The purpose was to evaluate prognostic factors of preoperative findings from MRI and arthroscopic evaluation on lower extremity performance at 1 year and patient-reported outcomes at 1 to 2 years after APM. The hypothesis was that medial compartment abnormalities would be prognostic for 1- and 2-year functional outcomes.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

This secondary analysis from the OMEX (Odense-Oslo Meniscectomy Versus Exercise) trial included 40 patients treated surgically. Regression analyses with adjustments for age, sex, and body mass index explored associations between MRI findings (tear complexity and extrusion), arthroscopic findings (tear length, cartilage injury, and amount of excised meniscal tissue), and the following: lower extremity performance tests and thigh muscle strength at 1 year and the 5 Knee injury and Osteoarthritis Outcome Score (KOOS) subscales at 1 and 2 years.

RESULTS

A complex meniscal tear was a significant and clinically relevant prognostic factor for worse KOOS Symptoms subscores at 2 years (mean, 14.1 points [95% CI, 6.1-22.2]). Meniscal extrusion of at least 11%, 25%, and 20% were significant and clinically relevant prognostic factors for worse KOOS Activities of Daily Living (ADL) subscores at 1 year and worse KOOS Sports and Recreation (Sports/Rec) subscores at 1 and 2 years, respectively. Tear lengths of at least 7.0 mm, 6.7 mm, and 6.5 mm were significant and clinically relevant prognostic factors for better KOOS Symptoms subscores at 1 year and better KOOS Sports/Rec subscores at 1 and 2 years, respectively. A cartilage injury in the medial compartment was a significant and clinically relevant prognostic factor for worse KOOS ADL and Quality of Life (QoL) subscores at 2 years (mean, 10.4 and 19.4 points, respectively [95% CI, 3.4-17.4 and 7.7-31.1, respectively]). More than 20% meniscal tissue excised was a significant and clinically relevant prognostic factor for worse KOOS Pain, Symptoms, ADL, and Sports/Rec subscores at 1 and 2 years (mean, 8.9-41.5 points [95% CI, 2.2-15.5 to 21.0-62.0]) and worse KOOS QoL subscores at 2 years (mean, 25.3 points [95% CI, 13.6-37.0]).

CONCLUSION

Complex meniscal tears, larger extrusion, cartilage injuries, and larger meniscal excision were significant and clinically relevant prognostic factors for worse outcomes 1 and 2 years after APM.

REGISTRATION

NCT01002794 (ClinicalTrials.gov identifier).