Anatomic is better than isometric posterior cruciate ligament tunnel placement based upon in vivo simulation.

PURPOSE: To elucidate the effects of various tibial and femoral attachment locations on the theoretical length changes and isometry of PCL grafts in healthy knees during in vivo weightbearing motion. METHODS: The intact knees of 14 patients were imaged using a combined magnetic resonance and dual fluoroscopic imaging technique while the patient performed a quasi-static lunge (0°-120° of flexion). The theoretical end-to-end distances of the 3-dimensional wrapping paths between 165 femoral attachments, including the anatomic anterolateral bundle (ALB), central attachment and posteromedial bundle (PMB) of the PCL, connected to an anterolateral, central, and posteromedial tibial attachment were simulated and measured. A descriptive heatmap was created to demonstrate the length changes on the medial condyle and formal comparisons were made between the length changes of the anatomic PCL and most isometric grafts. RESULTS: The most isometric graft, with approximately 3% length change between 0° and 120° of flexion, was located proximal to the anatomic femoral PCL attachments. Grafts with femoral attachments proximal to the isometric zone decreased in length with increasing flexion angles, whereas grafts with more distal attachments increased in length with increasing flexion angles. The ALB and central single-bundle graft demonstrated a significant elongation from 0° to 120° of flexion (p < 0.001). The PMB decreased in length between 0° and 60° of flexion after which the bundle increased in length to its maximum length at 120° (p < 0.001). No significant differences in length changes were found between either the ALB or PMB and the central graft, and between the ALB and PMB at flexion angles ≥ 60° (n.s.). CONCLUSIONS: The most isometric attachment was proximal to the anatomic PCL footprint and resulted in non-physiological length changes. Moving the femoral attachment locations of the PCL significantly affected length change patterns, whereas moving the tibia locations did not. The importance of anatomically positioned (i.e., distal to the isometric area) femoral PCL reconstruction locations to replicate physiological length changes is highlighted. These data can be used to optimize tunnel positioning in either single- or double-bundle and primary or revision PCL reconstruction cases. LEVEL OF EVIDENCE: IV.

An In Vivo Prediction of Anisometry and Strain in Anterior Cruciate Ligament Reconstruction - A Combined Magnetic Resonance and Dual Fluoroscopic Imaging Analysis.

PURPOSE: To evaluate the in vivo anisometry and strain of theoretical anterior cruciate ligament (ACL) grafts in the healthy knee using various socket locations on both the femur and tibia. METHODS: Eighteen healthy knees were imaged using magnetic resonance imaging and dual fluoroscopic imaging techniques during a step-up and sit-to-stand motion. The anisometry of the medial aspect of the lateral femoral condyle was mapped using 144 theoretical socket positions connected to an anteromedial, central, and posterolateral attachment site on the tibia. The 3-dimensional wrapping paths of each theoretical graft were measured. Comparisons were made between the anatomic, over the top (OTT), and most-isometric (isometric) femoral socket locations, as well as between tibial insertions. RESULTS: The area of least anisometry was found in the proximal-distal direction just posterior to the intercondylar notch. The most isometric attachment site was found midway on the Blumensaat line with approximately 2% and 6% strain during the step-up and sit-to-stand motion, respectively. Posterior femoral attachments resulted in decreased graft lengths with increasing flexion angles, whereas anterodistal attachments yielded increased lengths with increasing flexion angles. The anisometry of the anatomic, OTT and isometric grafts varied between tibial insertions (P < .001). The anatomic graft was significantly more anisometric than the OTT and isometric graft at deeper flexion angles (P < .001). CONCLUSIONS: An area of least anisometry was found in the proximal-distal direction just posterior to the intercondylar notch. ACL reconstruction at the isometric and OTT location resulted in nonanatomic graft behavior, which could overconstrain the knee at deeper flexion angles. Tibial location significantly affected graft strains for the anatomic, OTT, and isometric socket location. CLINICAL RELEVANCE: This study improves the knowledge on ACL anisometry and strain and helps surgeons to better understand the consequences of socket positioning during intra-articular ACL reconstruction.

Establishing Normal Variances and Expectations for Quadriceps Limb Symmetry Index Benchmarks Based on Time from Surgery After Anterior Cruciate Ligament Reconstruction.

The anticipated timeline for muscle strength as well as return to running and sports are some of the most common inquiries by patients undergoing anterior cruciate ligament reconstruction. Despite the popularity of this procedure, the answers to these inquiries are not well described in the literature. The purpose of this study was to evaluate the range of quadriceps strength percentage and function benchmarks at various points after anterior cruciate ligament reconstruction surgery based on sex, age, and graft. Design: Observational Cohort Study. Methods: Patients who underwent anterior cruciate ligament reconstruction (ACLR) were evaluated at various points after their surgery with handheld dynamometer assessments. Additional hop and balance testing was performed and patients were evaluated for clearance for running and sport via a physical therapist directed functional movement assessment (FMA). The progression of quadriceps symmetry throughout the postoperative period was examined with multi-level models, estimates of time to reach 70%, 80%, and 90% quadriceps symmetry were obtained from the fitted model. Results: A total of 164 patients were evaluated. Patients either received bone-tendon-bone (BTB) autograft (n=118) or BTB allograft (n=46) for their ACL graft. Average age was 31.1 years-of-age (SD: 13.6). Males undergoing ACLR using BTB autograft (n=53) were able to achieve 80% quadriceps symmetry earlier than females (n=65) (5.7 months vs 7.1 months), were cleared to return to run sooner (5.6 months vs 6.8 months) and passed an FMA exam earlier (8.5 months vs 10 months). Males undergoing ACLR with allograft (n=13) were able to achieve 80% quadriceps symmetry earlier than females (n=33) (3.9 months vs 5.4 months) and were cleared to run sooner (4.5 months vs 5.8 months). Conclusion: Patients undergoing BTB autograft obtain 80% quadriceps symmetry at an average of 5.7 months for males and 7.1 months for females. Individuals under the age of 25 obtain their quadriceps symmetry faster and are cleared to return to running faster than individuals over 25. Male sex is associated with decreased amount of time to obtain clearance for running and for full activity. Male sex is associated with decreased amount of time to regain quadriceps symmetry however this was not significant. Level of Evidence: 4 (Case series).

Fellow Efficiency During Anterior Cruciate Ligament Reconstruction Improves Over Time, Yet Is Less Than Experienced Physician Assistant But With No Significant Difference in Patient-Reported Outcomes.

Purpose: To evaluate the intraoperative efficiency and patient outcomes of anterior cruciate ligament reconstruction (ACLR) assisted by a sports medicine fellow over the course of the academic year compared with an experienced physician assistant (PA). Methods: A single-surgeon cohort of primary ACLRs with either bone-tendon-bone autograft or bone-tendon-bone allograft (without any other significant time-consuming procedures such as meniscectomy/repair) were evaluated using a patient registry system over 2 years assisted by an experienced PA compared with an orthopaedic surgery sports medicine fellow. There were 264 primary ACLRs included in this study. Outcomes included evaluation of surgical time, tourniquet time, and patient-reported outcome measures. Results: The surgical efficiency of the fellow (as measured by surgical time and tourniquet time) improved over each academic quarter. Patient-reported outcomes between the 2 first-assist groups showed no significant difference over 2 years with both ACL graft groups combined. ACLRs assisted by the PA showed shorter tourniquet times by 22.1% and shorter total surgical times by 11.9% compared with the sports medicine fellows when both grafts were combined (P < .001). The surgical and tourniquet times (minutes) for the fellow (standard deviation of surgical time 19.5-25.0 and tourniquet time 19.5-25.0) did not average out to be more efficient in any of the 4 quarters of the year compared with the PA-assisted group (standard deviation of surgical time 14.4-14.8 and tourniquet time 14.8-22.4). Autografts showed more efficient tourniquet (18.7%) and skin-to-skin surgical times (11.1%) in the PA group compared with the fellow group (P < .001). Allografts showed more efficient tourniquet (37.7%) and skin-to-skin surgical times (12.8%) in the PA group compared with the fellow group (P < .001). Conclusions: The surgical efficiency of the fellow during primary ACLRs improves over the academic year. Patient-reported outcomes are similar in cases assisted by the fellow compared with an experienced physician assistant. Cases assisted by the PA were performed more efficiently compared with the sports medicine fellow. Clinical Relevance: The intraoperative efficiency of a sports medicine fellow objectively improves over the academic year for primary ACLRs but may not be as efficient as an experienced advanced practice provider; however, there appears to be no significant differences in patient-reported outcome measures between the 2 groups. This helps quantify the time commitment for attendings and academic medical institutions as the "cost of education" of trainees such as fellows.

Return to Play After Shoulder Surgery in Professional Baseball Players: A Systematic Review and Meta-analysis.

Background: The current literature lacks an updated review examining return to play (RTP) and return to prior performance (RTPP) after shoulder surgery in professional baseball players. Purpose: To summarize the RTP rate, RTPP rate, and baseball-specific performance metrics among professional baseball players who underwent shoulder surgery. Study Design: Systematic review; Level of evidence, 4. Methods: A literature search was performed utilizing the PubMed, MEDLINE, and CINAHL databases and according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Inclusion criteria were English-language studies reporting on postoperative RTP and/or RTPP in professional baseball players who underwent shoulder surgery between 1976 and 2016. RTP rates, RTPP rates, and baseball-specific performance metrics were extracted from qualifying studies. A total of 2034 articles were identified after the initial search. Meta-analysis was performed where applicable, yielding weighted averages of RTP and RTPP rates and comparisons between pitchers and nonpitchers for each type of surgery. Baseball-specific performance metrics were reported as a narrative summary. Results: Overall, 26 studies featuring 1228 professional baseball players were included. Patient-level outcome data were available for 529 players. Surgical interventions included rotator cuff debridement (n = 197), rotator cuff repair (RCR; n = 43), superior labrum from anterior to posterior repair (n = 124), labral repair (n = 103), latissimus dorsi/teres major (LD/TM) repair (n = 21), biceps tenodesis (n = 17), coracoclavicular ligament reconstruction (n = 15), anterior capsular repair (n = 5), and scapulothoracic bursectomy (n = 4). Rotator cuff debridement was the most common surgical procedure, while scapulothoracic bursectomy was the least common (37.2% and 0.8% of interventions, respectively). Meta-analysis revealed that the RTP rate was highest for LD/TM repair (84.5%) and lowest for RCR (53.5%), while the RTPP rate was highest for LD/TM repair (100.0%) and lowest for RCR (27.9%). RTP and RTPP rates were generally higher for position players than for pitchers. Nonvolume performance metrics were unaffected by shoulder surgery, while volume statistics decreased or remained similar. Conclusion: RTP and RTPP rates among professional baseball players were modest after most types of shoulder surgery. Among surgical procedures commonly performed on professional baseball players, RTP and RTPP rates were highest for LD/TM repair and lowest for RCR.

Tunnel position and graft orientation in failed anterior cruciate ligament reconstruction: a clinical and imaging analysis.

PURPOSE: It has been reported that technical error in positioning the graft tunnel is the most common problem in anterior cruciate ligament (ACL) reconstruction. The objective of this study was to quantitatively evaluate femoral and tibial tunnel positions and intra-articular graft orientation of primary ACL reconstruction in patients who had undergone revision ACL reconstruction. We postulated that this patient cohort had a nonanatomically positioned tunnel and graft orientation. METHODS: Twenty-six patients who had undergone a revision ACL were investigated. Clinical magnetic resonance (MR) images prior to revision were analysed. Three-dimensional models of bones and tunnels on the femur and tibia were created. Intra-articular graft orientation was measured in axial, sagittal and coronal planes. Graft positions were measured on the tibial plateau as a percentage from anterior to posterior and medial to lateral; graft positions on the femur were measured using the quadrant method. RESULTS: Sagittal elevation angle for failed ACL reconstruction graft (69.6° ± 13.4°) was significantly greater (p < 0.05) than that of the native anteromedial (AM) and posterolateral (PL) bundles of the ACL (AM 56.2° ± 6.1°, PL 55.5° ± 8.1°). In the transverse plane, the deviation angle of the failed graft (37.3° ± 21.0°) was significantly greater than native ACL bundles. The tibial tunnel in this patient cohort was placed posteromedially and medially to the anatomical AM and PL bundles, respectively. The femoral tunnel was placed anteriorly to the anatomical AM and PL bundles. CONCLUSIONS: This study reveals that both the tibial and femoral tunnel positions and consequently the intra-articular graft orientation in this patient group with failed ACL reconstruction were nonanatomical when compared with native ACL values. The results can be used to improve tunnel placement in ACL reconstruction.

Medial patellar ossification after patellar instability: a radiographic finding indicative of prior patella subluxation/dislocation.

OBJECTIVE: To describe the correlation between medial patellar ossification and prior patella subluxation and/or dislocation. MATERIALS AND METHODS: A retrospective billing database search identified 544 patients who had been diagnosed with patellar instability over a 13-year period. One hundred twenty-eight patients met the inclusion criteria. After review by a staff orthopedic surgeon and two musculoskeletal radiologists, 28 patients were found to have medial patellar ossification. The size and location of medial patellar ossification was recorded. RESULTS: Of the 28 patients (20 males, eight females, age 13-66 years, mean 28 years) who were found to have medial patellar ossification, 22 had radiographs, 16 had magnetic resonance imaging, and ten had both. The medial patellar ossification ranged in size from 2 to 18 mm with an average of 6.8 mm. Twelve were located in the medial patellofemoral ligament (MPFL), 14 in the medial joint capsule, and two in both the MPFL and joint capsule. Twenty-seven of 28 patients had a single ossification, and one patient had two ossifications. The timing from injury to first imaging of the lesion ranged from 10 days to a chronic history (> or = 35 years) of patellar instability. CONCLUSION: Medial patellar ossification correlates with a history of prior patella subluxation and/or dislocation. The medial ossification can be seen within the MPFL or the medial joint capsule, suggesting remote injury to these structures. The presence of this lesion will prompt physicians to evaluate for patellar instability.

Return to Sport after Surgical Treatment of Lisfranc Injuries in Athletes: A Retrospective Case Series.

INTRODUCTION: A Lisfranc injury can be a devastating injury in athletes, and if inadequately treated, may lead to chronic pain and loss of function. The purpose of this study was to determine the rate and time until return to sport after surgical fixation for a ligamentous Lisfranc injury. We hypothesized that open reduction and screw fixation of a ligamentous Lisfranc injury can be a successful treatment in the athletic population and allow patients to return to sport at close to their preinjury level of play. METHODS: All patients who were analyzed underwent repair of a ligamentous Lisfranc injury with open reduction and screw fixation by a single surgeon, were between 18 - 40 years old at time of their final follow up, and were identified as being an athlete (either recreational or competitive). Eligible patients were given a questionnaire that included if they were able to return to sport, time until return to sport, subjective percentage of pre-injury level of play, current pain (0 - 10), and complications. RESULTS: Eleven patients were identified as athletes. Ten (91%) were available for follow-up with a mean of 36.5 months (range, 14 - 60). The average age was 25.4 years (range, 15 - 37) at time of surgery. Eighty percent (8/10) were able to return to sport. The average time until return to sport was 29.4 weeks (range, 22 - 52) with an average subjective value of their pre-injury level of play of 87% (range, 70 - 100%). However, 67% (6/9) of the athletes had occasional pain with sport with an average pain level of 2.1 (range, 0 - 5). Two patients had complications, a superficial infection and a deep vein thrombosis. CONCLUSION: Most athletes were able to return to sport after undergoing open reduction and internal fixation of a ligamentous Lisfranc injury by less than 30 weeks post-surgery with a subjective value of 87% of their previous function. However, the majority of the patients also experienced some residual pain with their respective sport. These findings suggested that athletes with a ligamentous Lisfranc injury can have reliably good outcomes with operative repair.

The effect of ACL deficiency on the end-to-end distances of the tibiofemoral ACL attachment during in vivo dynamic activity.

PURPOSE: To evaluate the effect of ACL deficiency on the in vivo changes in end-to-end distances and to determine appropriate graft fixation angles for commonly used tunnel positions in contemporary ACL reconstruction techniques. METHODS: Twenty-one patients with unilateral ACL-deficient and intact contralateral knees were included. Each knee was studied using a combined magnetic resonance and dual fluoroscopic imaging technique while the patients performed a dynamic step-up motion (~50° of flexion to extension). The end-to-end distances of the centers of the anatomic anteromedial (AM), posterolateral (PL) and single-bundle ACL reconstruction (SB-anatomic) tunnel positions were simulated and analyzed. Comparisons were made between the elongation patterns between the intact and ACL-deficient knees. Additionally, a maximum graft length change of 6% was used to calculate the deepest flexion fixation angle. RESULTS: ACL-deficient knees had significantly longer graft lengths when compared with the intact knees for all studied tunnel positions (p < 0.01). The end-to-end distances for the AM, PL and SB-anatomic grafts were significantly longer between 0-30° of flexion when compared with the intact knee by p < 0.05 for all. Six percent length change occurred with fixation of the AM bundle at 30° of flexion, PL bundle at 10° and the SB-anatomic graft at 20°. CONCLUSIONS: ACL-deficient knees had significantly longer in vivo end-to-end distances between 0°-30° of flexion for grafts at the AM, PL and SB-anatomic tunnel positions when compared with the intact knees. Graft fixation angles of <30° for the AM, <10° for the PL, and <20° for the SB-anatomic grafts may prevent permanent graft stretch.

The Role of Therapeutic Modalities in Surgical and Nonsurgical Management of Orthopaedic Injuries.

Rehabilitation professionals often use therapeutic modalities as a component of the surgical and nonsurgical management of orthopaedic injuries. Myriad therapeutic modalities, including cryotherapy, thermotherapy, ultrasonography, electrical stimulation, iontophoresis, and laser therapy, are available. Knowledge of the scientific basis of each modality and the principles of implementation for specific injuries enables musculoskeletal treatment providers to prescribe these modalities effectively. The selection of specific therapeutic modalities is based on their efficacy during a particular phase of rehabilitation. Therapeutic modalities are an adjunct to standard exercise and manual therapy techniques and should not be used in isolation.

Encapsulated Fat Necrosis Lesion Caused by Morel-Lavallée Lesion in a Professional Ice Hockey Player.

Morel-Lavallée (ML) lesions occur when subcutaneous tissue is stripped from fascia and replaced with hematoma or necrotic fat. Encapsulated fat necrosis lesions, which are rare, can occur with disruption of the blood supply in the subcutaneous area, which occurs with ML lesions. In this article, we report the case of a professional ice hockey player with an ML lesion that caused a symptomatic encapsulated fat necrosis lesion to develop. The encapsulated lesion required surgical removal.

An in Vivo Simulation of Isometry of the Anterolateral Aspect of the Healthy Knee.

BACKGROUND: To assess the isometry of theoretical lateral extra-articular reconstruction (LER), we evaluated theoretical grafts attached to various points on the lateral femoral condylar area and to either Gerdy's tubercle or the anatomic attachment site of the anterolateral ligament to the tibia. METHODS: In 18 subjects, healthy knees with no history of either injury or surgery involving the lower extremity were studied. The subjects performed a sit-to-stand motion (from approximately 90° of flexion to full extension), and each knee was studied using magnetic resonance and dual fluoroscopic imaging techniques. The 3-dimensional wrapping paths of each theoretical LER graft were measured. Grafts showing the least change in length during the sit-to-stand motion were considered to be the most isometric. RESULTS: The most isometric attachment site on the lateral femoral epicondyle to either of the studied tibial attachment sites was posterior-distal to the femoral attachment site of the fibular collateral ligament. The LER graft had a mean change in length of approximately 3%. Moving the femoral attachment site anteriorly resulted in increased length of the graft with increasing flexion; more posterior attachment sites resulted in decreased length with increasing flexion. Moving the attachment site in the proximal-distal direction had a less profound effect. Moving the tibial attachment site from Gerdy's tubercle to the tibial attachment site of the anterolateral ligament affected the overall isometric distribution on the lateral femoral epicondyle. CONCLUSIONS: The most isometric attachment site on the femur for an LER would be posterior-distal to the femoral attachment site of the fibular collateral ligament. Different length changes for LER grafts were identified with respect to different femoral attachment sites. Desirable graft fixation locations for treating anterolateral rotatory instability were found posterior-proximal to the femoral fibular collateral ligament attachment. CLINICAL RELEVANCE: The present data could be used both in biomechanical studies and in clinical studies as guidelines for planning LER surgical procedures.

The treatment of articular cartilage defects using the microfracture technique.

Chondral defects of the articular surface pose a challenging problem to the orthopedic surgeon. The goal of surgery is to alleviate pain, maximize function, and prevent degenerative changes in the future. A number of techniques have been described to treat these lesions. When considering the treatment options for chondral defects, the surgeon must consider the size, depth, location, and chronicity of the lesion. In addition, the overall alignment of the joint must be evaluated. Prior to treating chondral defects, it is important to understand the indications and contraindications for the microfracture technique. When indicated, the microfracture technique has many advantages over other surgical options. This technique is relatively easy to perform, cost effective, and has low patient morbidity. In addition, the microfracture technique does not burn any long-term bridges, enabling the surgeon to choose a different procedure to revise the chondral defect if the microfracture fails. It is important to understand the mechanism of healing by microfracture, including the effects of the local environment. The postoperative protocol used after the procedure may be as important as the surgery itself. Understanding the science behind the microfracture procedure will lead to better surgical technique and improved outcomes.

Shoulder instability in professional football players.

BACKGROUND: Shoulder instability is a common problem in American football players entering the National Football League (NFL). Treatment options include nonoperative and surgical stabilization. PURPOSE: This study evaluated how the method of treatment of pre-NFL shoulder instability affects the rate of recurrence and the time elapsed until recurrence in players on 1 NFL team. DESIGN: Retrospective cohort. METHODS: Medical records from 1980 to 2008 for 1 NFL team were reviewed. There were 328 players included in the study who started their career on the team and remained on the team for at least 2 years (mean, 3.9 years; range, 2-14 years). The history of instability prior to entering the NFL and the method of treatment were collected. Data on the occurrence of instability while in the NFL were recorded to determine the rate and timing of recurrence. RESULTS: Thirty-one players (9.5%) had a history of instability prior to entering the NFL. Of the 297 players with no history of instability, 39 (13.1%) had a primary event at a mean of 18.4 ± 22.2 months (range, 0-102 months) after joining the team. In the group of players with prior instability treated with surgical stabilization, there was no statistical difference in the rate of recurrence (10.5%) or the timing to the instability episode (mean, 26 months) compared with players with no history of instability. Twelve players had shoulder instability treated nonoperatively prior to the NFL. Five of these players (41.7%) had recurrent instability at a mean of 4.4 ± 7.0 months (range, 0-16 months). The patients treated nonoperatively had a significantly higher rate of recurrence (P = 0.02) and an earlier time of recurrence (P = 0.04). The rate of contralateral instability was 25.8%, occurring at a mean of 8.6 months. CONCLUSION: Recurrent shoulder instability is more common in NFL players with a history of nonoperative treatment. Surgical stabilization appears to restore the rate and timing of instability to that of players with no prior history of instability.

Endoscopic repair of gluteus medius tendon tears of the hip.

BACKGROUND: Tears of the gluteus medius tendon at the greater trochanter have been termed "rotator cuff tears of the hip." Previous reports have described the open repair of these lesions. HYPOTHESIS: Endoscopic repair of gluteus medius tears results in successful clinical outcomes in the short term. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Of 482 consecutive hip arthroscopies performed by the senior author, 10 patients with gluteus medius tears repaired endoscopically were evaluated prospectively. Perioperative data were analyzed on this cohort of patients. There were 8 women and 2 men, with an average age of 50.4 years (range, 33-66 years). Patients had persistent lateral hip pain and abductor weakness despite extensive conservative measures. Diagnosis was made by physical examination and magnetic resonance imaging and was confirmed at the time of endoscopy in all cases. At the most recent follow-up, patients completed the Modified Harris Hip Score and Hip Outcomes Score surveys. RESULTS: At an average follow-up of 25 months (range, 19-38 months), all 10 patients had complete resolution of pain; 10 of 10 regained 5 of 5 motor strength in the hip abductors. Modified Harris Hip Scores at 1 year averaged 94 points (range, 84-100), and Hip Outcomes Scores averaged 93 points (range, 85-100). There were no adverse complications after abductor repairs. Seven of 10 patients said their hip was normal, and 3 said their hip was nearly normal. CONCLUSION: With short-term follow-up, endoscopic repair of gluteus medius tendon tears of the hip appears to provide pain relief and return of strength in select patients who have failed conservative measures. Further long-term follow-up is warranted to confirm the clinical effectiveness of this procedure.

Cross-sectional analysis of the iliopsoas tendon and its relationship to the acetabular labrum: an anatomic study.

BACKGROUND: Hip pain in patients with normal bony anatomy and anterior labral injury may be related to compression of the iliopsoas tendon across the anterior capsulolabral complex. No attempts to characterize the 3-dimensional anatomy of the iliopsoas tendon and its relationship to the acetabular labrum have been reported to date. HYPOTHESIS: The iliopsoas tendon directly overlies the capsulolabral complex. Contribution of the muscle belly and tendon to the overall circumference at the level of the labrum is approximately the same. STUDY DESIGN: Descriptive laboratory study. MATERIALS AND METHODS: Eight hip joints were dissected and cross-sectional measurements of the iliopsoas muscle-tendon complex were performed using digital calipers and image analysis software. RESULTS: The iliopsoas tendon in all specimens was located directly anterior to the anterosuperior capsulolabral complex at the 2 to 3 o'clock position. The overall length of the iliopsoas tendon from the lesser trochanter to the acetabular labrum was 75.4 +/- 0.9 mm. The circumference of the iliopsoas tendon at the lesser trochanter was 25.5 +/- 2.6 mm, the iliopsoas tendon at the level of the labrum was 28.4 +/- 2.8 mm, and the iliopsoas tendon-muscle belly complex at the level of the labrum was 63.8 +/- 7.4 mm. At the level of the labrum, the iliopsoas is composed of 44.5% tendon and 55.5% muscle belly. CONCLUSION: The close anatomic relationship of the iliopsoas tendon to the anterior capsulolabral complex suggests that iliopsoas pathologic changes at this level may lead to labral injury. Additionally, these data suggest that at the level of the labrum, 45% of the tendon-muscle belly complex should be released to release the entire tendinous portion. CLINICAL RELEVANCE: Knowledge of the cross-sectional anatomy of the iliopsoas tendon and its relationship to the acetabular labrum will better assist surgeons in treating lesions associated with iliopsoas injury.

The effectiveness of warfarin dosing from a nomogram compared with house staff dosing.

The purpose of this study is to address the safety and efficacy of a warfarin dosing nomogram. Patients undergoing hip or knee arthroplasty were randomized to warfarin dosed by nomogram (n = 106) or by house staff (n = 110) during their hospital stay. The average daily dose of warfarin was 4.14 mg for the nomogram group and 4.18 mg for the house staff group. On postoperative day 4, the average international normalized ratio was 1.55 in the nomogram group compared with 1.59 in the house staff group. On postoperative day 4, 19.1% of the patients in the nomogram group had a therapeutic international normalized ratio, compared with 14.7% in the house staff group. There were no differences in bleeding or thrombotic complications in the 2 groups. This nomogram appears to be both safe and effective.