Achilles Tendon Repairs: Identification of Risk Factors for and Economic Impact of Complications and Reoperation.

BACKGROUND: Compared with nonoperative management, Achilles tendon repair is associated with increased rates of complications and increased initial healthcare cost. However, data are currently lacking on the risk factors for these complications and the added healthcare cost associated with common preoperative comorbidities. HYPOTHESIS: Identify the independent risk factors for complications and reoperation after acute Achilles tendon repair and calculate the added cost of care associated with having each preoperative risk factor. STUDY DESIGN: Retrospective cohort study. LEVEL OF EVIDENCE: Level 3. METHODS: A retrospective review of a large commercial claims database was performed to identify patients who underwent primary operative management for Achilles tendon rupture between 2007 and 2016. The primary outcome measures of the study were risk factors for (1) postoperative complications, (2) revision surgery, and (3) increased healthcare resource utilization. RESULTS: A total of 50,279 patients were included. The overall complication rate was 2.7%. The most common 30-day complication was venous thromboembolism (1.2%). The rate of revision surgery was 2.5% at 30 days and 4.3% at 2 years. Independent risk factors for 30-day complications in our cohort included increasing age, hyperlipidemia, hypertension, female sex, obesity, and diabetes. Independent risk factors for revision surgery within 2 years included female sex, tobacco use, hypertension, obesity, and the presence of any postoperative complication. The average 5-year cost of operative intervention was $17,307. The need for revision surgery had the largest effect on 5-year overall cost, increasing it by $6776.40. This was followed by the presence of a postoperative complication ($3780), female sex ($3207.70), and diabetes ($3105). CONCLUSION: Achilles tendon repair is a relatively low-risk operation. Factors associated with postoperative complications include increasing age, hyperlipidemia, hypertension, female sex, obesity, and diabetes. Factors associated with the need for revision surgery include female sex, hypertension, obesity, and the presence of any postoperative complication. Female sex, diabetes, the presence of any complication, and the need for revision surgery had the largest added costs associated with them. CLINICAL RELEVANCE: Surgeons can use this information for preoperative decision-making and during the informed consent process.

Comparison of Autologous Chondrocyte Implantation and Osteochondral Allograft Transplantation of the Knee in a Large Insurance Database: Reoperation Rate, Complications, and Cost Analysis.

OBJECTIVE: To compare (1) the reoperation rates, (2) risk factors for reoperation, (3) 30-day complication rates, and (4) cost differences between autologous chondrocyte implantation (ACI) and osteochondral allograft transplantation (OCA) of the knee in a large insurance database. DESIGN: Subjects who underwent knee ACI (Current Procedural Terminology [CPT] code 27412) or OCA (CPT code 27415) with minimum 2-year follow-up were queried from a national insurance database. Reoperation was defined by ipsilateral knee procedure after index surgery. Multivariate logistic regression models were built to determine the effect of independent variables (age, sex, tobacco use, obesity, diabetes, and concomitant osteotomy) on reoperation rates. The 30-day complication rates were assessed using ICD-9-CM codes. The cost of the procedures per patient was calculated. Statistical comparisons were made. All P values were reported with significance set at P < 0.05. RESULTS: A total of 909 subjects (315 ACI and 594 OCA) were included (mean follow-up 39.2 months). There was a significantly higher reoperation rate after index ACI compared with OCA (67.6% vs. 40.4%, P < 0.0001). Concomitant osteotomy at the time of index procedure significantly reduced the risk for reoperation in both groups (odds ratio [OR] 0.2, P < 0.0001 and OR 0.2, P = 0.009). The complication rates were similar between ACI (1.6%) and OCA (1.2%) groups (P = 0.24). Day of surgery payments were significantly higher after ACI compared with OCA (P = 0.013). CONCLUSIONS: Autologous chondrocyte implantation had significantly higher reoperation rates and cost with similar complication rates compared with OCA. Concomitant osteotomy significantly reduced the risk for reoperation in both groups.

Assessment of the reliability of a non-invasive elbow valgus laxity measurement device.

PURPOSE: The purpose of this study was to assess the reliability of a new objective measurement tool to measure the valgus stress laxity of the ulnar collateral ligament (UCL) of the elbow, the "Elbow Tester". The anterior oblique portion of the ulnar collateral ligament (UCL) of the elbow is the primary static restraint to valgus stress during the overhead throwing motion. The main research question was if the "Elbow Tester" that we have developed was reliable and reproducible for further use in research and daily practice. METHODS: Three different examiners tested both elbows of 11 volunteers for UCL laxity. Each elbow was tested 5 times using a standard 2 Nm valgus load, and 3 times using a manual maximum valgus load. One examiner tested the volunteers again 1 week later. The outcomes of elbow valgus laxity were compared between examiners. The intraobserver reliability was assessed using an intraclass correlation coefficient (ICC) and interobserver reliability was also assessed with a mixed model repeated ANOVA test. RESULTS: The device demonstrated a high level of intraobserver reliability with both the 2 Nm valgus force and manual maximum valgus force, using a minimum of three trials as determined by an ICC > 0.9 for all examiners. The interobserver reliability was moderate using the 2 Nm valgus load with an ICC value of 0.72 and significant different outcomes of elbow valgus laxity amongst examiners (p < 0.01). A high interobserver reliability (ICC value of 0.90) was observed using manual maximum valgus force and no differences between outcomes (p > 0.53). CONCLUSION: The noninvasive valgus elbow tester demonstrates high interobserver and intraobserver reliability using manual maximum valgus force and can be used for further research and daily practice.

Costs, Complications, and Reoperations Associated With Primary Arthroscopic Rotator Cuff Repair With or Without Acromioplasty and/or Biceps Tenodesis.

PURPOSE: To evaluate the reoperations, complications, and costs up to 5 years following arthroscopic rotator cuff repair (RCR) alone, with acromioplasty (acro), with biceps tenodesis (BT), or with both acro and BT. METHODS: We queried the MarketScan database to identify patients who underwent RCR from 2007 to 2016. Patients were stratified into groups based on concomitant procedures (acro and/or BT) performed on the same day as index RCR. Reoperations, complications, and costs were followed for 5 years post-index procedure. Patients without laterality codes were excluded. A multivariate logistic regression analysis was used to control for confounding factors. RESULTS: This study identified 147,838 patients (mean age, 53.1 years; standard deviation, 8.3 years) who underwent primary RCR. Patients were stratified into 4 groups: (1) RCR only, (2) RCR + acro, (3) RCR + BT, and (4) RCR + acro + BT. Patients in the RCR only group experienced the highest rate of unadjusted overall postoperative complications (17.2%) versus the other groups (RCR + acro 16.4%, RCR + BT 15.1%, RCR + acro + BT 16.2%, P < .0161). The RCR only group also experienced a significantly greater number of reoperations on the ipsilateral shoulder (P < .0001), whereas the RCR + acro + BT had the highest costs at all timepoints. In the regression analysis, there was no significant differences between complications and reoperations between any groups. After adjusting for covariates, the performance of a BT with an RCR and acromioplasty led to increased costs (odds ratio, 1.47, 1.37-1.59, P < .001). CONCLUSIONS: Concomitant biceps tenodesis does lead to higher total healthcare costs, both in the shorter and longer terms. When adjusting for confounding factors, the performance of concomitant biceps tenodesis with rotator cuff repair does not lead to a difference in postoperative complication rate or risk for revision surgery. LEVEL OF EVIDENCE: Level IV, economic analysis.

Comparing Meniscectomy and Meniscal Repair: A Matched Cohort Analysis Utilizing a National Insurance Database.

BACKGROUND: Meniscal repair leads to improved patient outcomes compared with meniscectomy in small case series. PURPOSE: To compare the reoperation rates, 30-day complication rates, and cost differences between meniscectomy and meniscal repair in a large insurance database. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A national insurance database was queried for patients who underwent meniscectomy (Current Procedural Terminology [CPT] code 29880 or 29881) or meniscal repair (CPT code 29882 or 29883) in the outpatient setting and who had a minimum 2-year follow-up. Patients without confirmed laterality and patients who underwent concomitant ligament reconstruction were excluded. Reoperation was defined by ipsilateral knee procedure after the index surgery. The 30-day postoperative complication rates were assessed using the International Classification of Diseases, 9th Revision, Clinical Modification codes. The cost of the procedures per patient was calculated. Propensity score matching was utilized to create matched cohorts with similar characteristics. Statistical comparisons of cohort characteristics, reoperations, postoperative complications, and payments were made. All P values were reported with significance set at P < .05. RESULTS: A total of 27,580 patients (22,064 meniscectomy and 5516 meniscal repair; mean age, 29.9 ± 15.1 years; 41.2% female) were included in this study with a mean follow-up of 45.6 ± 21.0 months. The matched groups were similar with regard to characteristics and comorbidities. There were significantly more patients who required reoperation after index meniscectomy compared with meniscal repair postoperatively (5.3% vs 2.1%; P < .001). Patients undergoing meniscectomy were also significantly more likely to undergo any ipsilateral meniscal surgery (P < .001), meniscal transplantation (P = .005), or total knee arthroplasty (P = .001) postoperatively. There was a significantly higher overall 30-day complication rate after meniscal repair (1.2%) compared with meniscectomy (0.82%; P = .011). The total day-of-surgery payments was significantly higher in the repair group compared with the meniscectomy group ($7094 vs $5423; P < .001). CONCLUSION: Meniscal repair leads to significantly lower rates of reoperation and higher rates of early complications with a higher total cost compared with meniscectomy in a large database study.

Diagnostic Accuracy of 3 Physical Examination Tests in the Assessment of Hip Microinstability.

BACKGROUND: Hip microinstability is a diagnosis gaining increasing interest. Physical examination tests to identify microinstability have not been objectively investigated using intraoperative confirmation of instability as a reference standard. PURPOSE: To determine the test characteristics and diagnostic accuracy of 3 physical examination maneuvers in the detection of hip microinstability. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: A review was conducted of 194 consecutive hip arthroscopic procedures performed by a sports medicine surgeon at a tertiary-care academic center. Physical examination findings of interest, including the abduction-hyperextension-external rotation (AB-HEER) test, the prone instability test, and the hyperextension-external rotation (HEER) test, were obtained from prospectively collected data. The reference standard was intraoperative identification of instability based on previously published objective criteria. Test characteristics, including sensitivity, specificity, positive and negative predictive values, and accuracy, were calculated for each test as well as for combinations of tests. RESULTS: A total of 109 patients were included in the analysis. The AB-HEER test was most accurate, with a sensitivity of 80.6% (95% CI, 70.8%-90.5%) and a specificity of 89.4% (95% CI, 80.5%-98.2%). The prone instability test had a low sensitivity (33.9%) but a very high specificity (97.9%). The HEER test performed second in both sensitivity (71.0%) and specificity (85.1%). The combination of multiple tests with positive findings did not yield significantly greater accuracy. All tests had high positive predictive values (range, 86.3%-95.5%) and moderate negative predictive values (range, 52.9%-77.8%). When all 3 tests had positive findings, there was a 95.0% (95% CI, 90.1%-99.9%) chance that the patient had microinstability. CONCLUSION: The AB-HEER test most accurately predicted hip instability, followed by the HEER test and the prone instability test. However, the high specificity of the prone instability test makes it a useful test to "rule in" abnormalities. A positive result from any test predicted hip instability in 86.3% to 90.9% of patients, but a negative test result did not conclusively rule out hip instability, and other measures should be considered in making the diagnosis. The use of these tests may aid the clinician in diagnosing hip instability, which has been considered a difficult diagnosis to make because of its dynamic nature.

Biochemical and Cellular Assessment of Acetabular Chondral Flaps Identified During Hip Arthroscopy.

PURPOSE: To analyze chondral flaps debrided during hip arthroscopy to determine their biochemical and cellular composition. METHODS: Thirty-one full-thickness acetabular chondral flaps were collected during hip arthroscopy. Biochemical analysis was undertaken in 21 flaps from 20 patients, and cellular viability was determined in 10 flaps from 10 patients. Biochemical analysis included concentrations of (1) DNA (an indicator of chondrocyte content), (2) hydroxyproline (an indicator of collagen content), and (3) glycosaminoglycan (an indicator of chondrocyte biosynthesis). Higher values for these parameters indicated more healthy tissue. The flaps were examined to determine the percentage of viable chondrocytes. RESULTS: The percentage of acetabular chondral flap specimens that had concentrations within 1 SD of the mean values reported in previous normal cartilage studies was 38% for DNA, 0% for glycosaminoglycan, and 43% for hydroxyproline. The average cellular viability of our acetabular chondral flap specimens was 39% (SD, 14%). Only 2 of the 10 specimens had more than half the cells still viable. There was no correlation between (1) the gross examination of the joint or knowledge of the patient's demographic characteristics and symptoms and (2) biochemical properties and cell viability of the flap, with one exception: a degenerative appearance of the surrounding cartilage correlated with a higher hydroxyproline concentration. CONCLUSIONS: Although full-thickness acetabular chondral flaps can appear normal grossly, the biochemical properties and percentage of live chondrocytes in full-thickness chondral flaps encountered in hip arthroscopy show that this tissue is not normal. CLINICAL RELEVANCE: There has been recent interest in repairing chondral flaps encountered during hip arthroscopy. These data suggest that acetabular chondral flaps are not biochemically and cellularly normal. Although these flaps may still be valuable mechanically and/or as a scaffold in some conductive or inductive capacity, further study is required to assess the clinical benefit of repair.

A quantitative assessment of the insertional footprints of the hip joint capsular ligaments and their spanning fibers for reconstruction.

Quantitative descriptions of the hip joint capsular ligament insertional footprints have been reported. Using a three-dimensional digitizing system, and computer modeling, the area, and dimensions of the three main hip capsular ligaments and their insertional footprints were quantified in eight cadaveric hips. The iliofemoral ligament (ILFL) attaches proximally to the anterolateral supra-acetabular region (mean area = 4.2 cm(2)). The mean areas of the ILFL lateral and medial arm insertional footprints are 4.8 and 3.1 cm(2), respectively. The pubofemoral ligament (proximal footprint mean area = 1.4 cm(2)) blends with the medial ILFL anteriorly and the proximal ischiofemoral ligament (ISFL) distally without a distal bony insertion. The proximal and distal ISFL footprint mean areas are 6.4 and 1.2 cm(2), respectively. The hip joint capsular ligaments have consistent anatomic and insertional patterns. Quantification of the ligaments and their attachment sites may aid in improving anatomic repairs and reconstructions of the hip joint capsule using open and/or arthroscopic techniques.

Evaluation of formal methods in hip joint center assessment: an in vitro analysis.

BACKGROUND: The hip joint center is a fundamental landmark in the identification of lower limb mechanical axis; errors in its location lead to substantial inaccuracies both in joint reconstruction and in gait analysis. Actually in Computer Aided Surgery functional non-invasive procedures have been tested in identifying this landmark, but an anatomical validation is scarcely discussed. METHODS: A navigation system was used to acquire data on eight cadaveric hips. Pivoting functional maneuver and hip joint anatomy were analyzed. Two functional methods - both with and without using the pelvic tracker - were evaluated: specifically a sphere fit method and a transformation techniques. The positions of the estimated centers with respect to the anatomical center of the femoral head, the influence of this deviation on the kinematic assessment and on the identification of femoral mechanical axis were analyzed. FINDINGS: We found that the implemented transformation technique was the most reliable estimation of hip joint center, introducing a - Mean (SD) - difference of 1.6 (2.7) mm from the anatomical center with the pelvic tracker, whereas sphere fit method without it demonstrated the lowest accuracy with 25.2 (18.9) mm of deviation. Otherwise both the methods reported similar accuracy (<3mm of deviation). INTERPRETATION: The functional estimations resulted in the best case to be in an average of less than 2mm from the anatomical center, which corresponds to angular deviations of the femoral mechanical axis smaller than 1.7 (1.3) degrees and negligible errors in kinematic assessment of angular displacements.

In-vitro experimental assessment of a new robust algorithm for hip joint centre estimation.

Hip joint centre (HJC) localization is used in several biomedical applications, such as movement analysis and computer-assisted orthopaedic surgery. The purpose of this study was to validate in vitro a new algorithm (MC-pivoting) for HJC computation and to compare its performances with the state-of-the-art (least square approach-LSA). The MC-pivoting algorithm iteratively searches for the 3D coordinates of the point belonging to the femoral bone that, during the circumduction of the femur around the hip joint (pivoting), runs the minimum length trajectory. The algorithm was initialized with a point distribution that can be considered close to a Monte Carlo simulation sampling all around the LSA estimate. The performances of the MC-pivoting algorithm, compared with LSA, were evaluated with tests on cadavers. Dynamic reference frames were applied on both the femur and the pelvis and were tracked by an optical localizer. Results proved the algorithm accuracy (1.7mm+/-1.6, 2.3-median value+/-quartiles), reliability (smaller upper quartiles of the errors distribution with respect to LSA) and robustness (reduction of the errors also in case of large pelvis displacements).