Two-year clinical outcomes and complication rates in anatomic and reverse shoulder arthroplasty implanted with Exactech GPS intraoperative navigation.

INTRODUCTION: We compared the 2-year clinical outcomes of both anatomic and reverse total shoulder arthroplasty (ATSA and RTSA) using intraoperative navigation compared to traditional positioning techniques. We also examined the effect of glenoid implant retroversion on clinical outcomes. HYPOTHESIS: In both ATSA and RTSA, computer navigation would be associated with equal or better outcomes with fewer complications. Final glenoid version and degree of correction would not show outcome differences. MATERIAL AND METHODS: A total of 216 ATSAs and 533 RTSAs were performed using preoperative planning and intraoperative navigation with a minimum of 2-year follow-up. Matched cohorts (2:1) for age, gender, and follow-up for cases without intraoperative navigation were compared using all standard shoulder arthroplasty clinical outcome metrics. Two subanalyses were performed on navigated cases comparing glenoids positioned greater or less than 10° of retroversion and glenoids corrected more or less than 15°. RESULTS: For ASTA, no statistical differences were found between the navigated and non-navigated cohorts for postoperative complications, glenoid implant loosening, or revision rate. No significant differences were seen in any of the ATSA outcome metrics besides higher internal and external rotation in the navigated cohort. For RTSA, the navigated cohort showed an ARR of 1.7% (95% CI 0%, 3.4%) for postoperative complications and 0.7% (95% CI 0.1%, 1.2%) for dislocations. No difference was found in the revision rate, glenoid implant loosening, acromial stress fracture rates, or scapular notching. Navigated RTSA patients demonstrated significant improvements over non-navigated patients in internal rotation, external rotation, maximum lifting weight, the Simple Shoulder Test (SST), Constant, and Shoulder Arthroplasty Smart (SAS) scores. For the navigated subcohorts, ATSA cases with a higher degree of final retroversion showed significant improvement in pain, Constant, American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES), SST, University of California-Los Angeles shoulder score (UCLA), and Shoulder Pain and Disability Index (SPADI) scores. No significant differences were found in the RTSA subcohort. Higher degrees of version correction showed improvement in external rotation, SST, and Constant scores for ATSA and forward elevation, internal rotation, pain, SST, Constant, ASES, UCLA, SPADI, and SAS scores for RTSA. CONCLUSION: The use of intraoperative navigation shoulder arthroplasty is safe, produces at least equally good outcomes at 2 years as standard instrumentation does without any increased risk of complications. The effect of final implant position above or below 10° of glenoid retroversion and correction more or less than 15° does not negatively impact outcomes.

Subscapularis tenotomy versus lesser tuberosity osteotomy during total shoulder arthroplasty for primary osteoarthritis: a prospective, randomized controlled trial.

BACKGROUND: There is no current consensus on subscapularis mobilization during total shoulder arthroplasty. The purpose of this prospective, randomized controlled trial was to compare functional and radiographic outcomes of the more traditional subscapularis tenotomy (ST) versus lesser tuberosity osteotomy (LTO). METHODS: This study enrolled 60 shoulders in 59 patients with primary osteoarthritis. Thirty shoulders were preoperatively randomized to each group. Preoperative and 6-week, 3-month, 6-month, and 1-year postoperative data were collected. Ultrasound was performed at 3 months to evaluate subscapularis healing in tenotomy subjects, whereas radiographs were used to evaluate osteotomy healing. Intraoperative data included operative time, tenotomy or osteotomy repair time, and osteotomy thickness. RESULTS: No significant differences in range of motion or clinical outcomes occurred at baseline or 1 year postoperatively between the 2 groups. The mean total case duration for ST was significantly less than that for LTO (129.3 minutes vs 152.7 minutes), along with a significantly shorter subscapularis repair time for ST (34.3 minutes vs 39.3 minutes, P = .024). At final follow-up, 27 of 29 LTO shoulders (93.1%) showed bone-to-bone healing on radiographs, whereas 26 of 30 ST shoulders (86.7%) had no full-thickness tear of the subscapularis on ultrasound at 3 months. CONCLUSIONS: Both techniques produced successful objective and subjective clinical outcomes. LTO heals more reliably than ST. Mean total case and subscapularis repair times were significantly greater for LTO than for ST.

Labrum and rotator cuff injuries in the throwing athlete.

The large amount of force imparted across the shoulder during the act of throwing makes the glenohumeral joint highly susceptible to injury in the athlete performing overhead throwing motions. The bony incongruity of the shoulder enables greater range of motion than any other joint in the body, but it also results in significant strain on the surrounding soft tissues during the throwing motion. Throwers can present with acute injuries, but more commonly they suffer from chronic overuse conditions resulting from repetitive overload. Proper management requires early recognition with treatment directed toward the athlete's safe return to sports. Failure to institute an appropriate management strategy may result in significant complications, including prolonged disability, progression of symptoms, and further injury. We discuss the functional anatomy, pathophysiology, clinical presentation, evaluation, and treatment of common injuries of the glenoid labrum and rotator cuff in the overhead throwing athlete.

The curveball as a risk factor for injury: a systematic review.

CONTEXT: The curveball is regarded by many as a potential risk factor for injury in youth baseball pitchers. OBJECTIVE: To critically evaluate the scientific evidence regarding the curveball and its impact on pitching biomechanics and the overall risk of arm injuries in baseball pitchers. STUDY TYPE: Systematic review. LEVEL OF EVIDENCE: Level 3. DATA SOURCES: Ovid MEDLINE from 1946 to 2012. STUDY SELECTION: Ten biomechanical studies on kinematic or electromyographic analysis of pitching a curveball were included, as well as 5 epidemiologic studies that assessed pain or injury incidence in pitchers throwing the curveball. DATA EXTRACTION: When possible, demographic, methodology, kinetics, and kinematics variables and pain/injury incidence were compiled. RESULTS: Two biomechanical studies found greater horizontal adduction of the shoulder at ball release and less shoulder internal torque during the curveball pitching motion. Two studies demonstrated less proximal force and less torque at the elbow as the arm accelerated when throwing a curveball compared with a fastball, as well as greater supination of the forearm and less wrist extension. Electromyographic data suggested increased activity of extensor and supinator muscles for curveballs. No studies found increased force or torque about the elbow or shoulder. Three epidemiologic studies showed no significant association between pitching a curveball and upper extremity pain or injury. One retrospective epidemiologic study reported a 52% increase in shoulder pain in pitchers throwing a curveball, although this may have been due to confounders. CONCLUSION: Despite much debate in the baseball community about the curveball's safety in youth pitchers, limited biomechanical and most epidemiologic data do not indicate an increased risk of injury when compared with the fastball.

Mapping the articular contact area of the long head of the biceps tendon on the humeral head.

The purpose of this investigation was to calculate the contact surface area of the long head of the biceps (LHB) in neutral position and abduction. We sought to determine whether the LHB articulates with the humeral head in a consistent pattern comparing articular contact area in neutral position and abduction. Eleven fresh frozen matched cadaveric shoulders were analyzed. The path of the biceps tendon on the articular surface of the humeral head and the total articular surface were digitized using a MicronTracker 2 H3-60 three-dimensional optical tracker. Contact surface area was significantly less in abduction than in neutral position (P = 0.002) with a median ratio of 41% (36%, 47.5%). Ratios of contact area in neutral position to full articular surface area were consistent between left and right shoulders (rho = 1, P = 0.017) as were ratios of abduction area to full articular surface area (rho = 0.97, P = 0.005). The articular contact surface area is significantly greater in neutral position than abduction. The ratios of articular contact surface areas to total humeral articular surface areas have a narrow range and are consistent between left and right shoulders of the same cadaver.

A comprehensive approach to glenohumeral arthritis.

Arthritis of the glenohumeral joint is a common cause of debilitating shoulder pain, affecting up to one-third of patients older than 60 years. It is progressive in nature and characterized by irreversible destruction of the humeral head and glenoid articular surfaces. Inflammation of the surrounding soft tissues is often present and further contributes to the pain caused by the disease process. A number of primary (degenerative) and secondary pathological processes may result in this condition. Patients often present with a long history of shoulder pain, stiffness, and/or loss of function, or may have acute exacerbations of this chronic condition. Initial conservative management is aimed at improving pain and restoring function. Surgical treatment is indicated in severe or refractory cases when nonoperative management has failed. Shoulder replacement now accounts for the third most common joint replacement surgery after the hip and knee. This article reviews the basic science and clinical management of osteoarthritis of the glenohumeral joint.

Acromioclavicular osteoarthritis: a common cause of shoulder pain.

Osteoarthritis of the acromioclavicular joint is a frequent cause of shoulder pain and can result in significant debilitation. It is the most common disorder of the acromioclavicular joint and may arise from a number of pathologic processes, including primary (degenerative), posttraumatic, inflammatory, and septic arthritis. Patients often present with nonspecific complaints of pain located in the neck, shoulder, and/or arm, further complicating the clinical picture. A thorough understanding of the pertinent anatomy, disease process, patient history, and physical examination is crucial to making the correct diagnosis and formulating a treatment plan. Initial nonoperative management is aimed at relieving pain and restoring function. Typical treatments include anti-inflammatory medications, physical therapy, and injections. Patients who continue to exhibit symptoms after appropriate nonsurgical treatment may be candidates for operative resection of the distal clavicle through either open or arthroscopic techniques.

Influence of Rotator Cuff Tear Size and Repair Technique on the Creation and Management of Dog Ear Deformities in a Transosseous-Equivalent Rotator Cuff Repair Model.

BACKGROUND: Redundancies in the rotator cuff tissue, commonly referred to as "dog ear" deformities, are frequently encountered during rotator cuff repair. Knowledge of how these deformities are created and their impact on rotator cuff footprint restoration is limited. PURPOSE: The goals of this study were to assess the impact of tear size and repair method on the creation and management of dog ear deformities in a human cadaveric model. STUDY DESIGN: Controlled laboratory study. METHODS: Crescent-shaped tears were systematically created in the supraspinatus tendon of 7 cadaveric shoulders with increasing medial to lateral widths (0.5, 1.0, and 1.5 cm). Repair of the 1.5-cm tear was performed on each shoulder with 3 methods in a randomized order: suture bridge, double-row repair with 2-mm fiber tape, and fiber tape with peripheral No. 2 nonabsorbable looped sutures. Resulting dog ear deformities were injected with an acrylic resin mixture, digitized 3-dimensionally (3D), and photographed perpendicular to the footprint with calibration. The volume, height, and width of the rotator cuff tissue not in contact with the greater tuberosity footprint were calculated using the volume injected, 3D reconstructions, and calibrated photographs. Comparisons were made between tear size, dog ear measurement technique, and repair method utilizing 2-way analysis of variance and Student-Newman-Keuls multiple-comparison tests. RESULTS: Utilizing 3D digitized and injection-derived volumes and dimensions, anterior dog ear volume, height, and width were significantly smaller for rotator cuff repair with peripheral looped sutures compared with a suture bridge (P < .05) or double-row repair with 2-mm fiber tape alone (P < .05). Similarly, posterior height and width were significantly smaller for repair with looped peripheral sutures compared with a suture bridge (P < .05). Dog ear volumes and heights trended larger for the 1.5-cm tear, but this was not statistically significant. CONCLUSION: When combined with a standard transosseous-equivalent repair technique, peripheral No. 2 nonabsorbable looped sutures significantly decreased the volume, height, and width of dog ear deformities, better restoring the anatomic footprint of the rotator cuff. CLINICAL RELEVANCE: Dog ear deformities are commonly encountered during rotator cuff repair. Knowledge of a repair technique that reliably decreases their size, and thus increases contact at the anatomic footprint of the rotator cuff, will aid sports medicine surgeons in the management of these deformities.

The Impact of Fatigue on the Kinematics of Collegiate Baseball Pitchers.

BACKGROUND: Many factors are believed to contribute to throwing injuries in baseball pitchers, in particular overuse and poor throwing mechanics. The impact of fatigue on pitching biomechanics in live-game situations is not well understood. HYPOTHESIS: Pitchers will demonstrate significant deviation in their pitching motions with increasing levels of fatigue. STUDY DESIGN: Descriptive laboratory study. METHODS: Eleven National Collegiate Athletic Association (NCAA) Division I collegiate baseball pitchers were filmed in multiple live-game situations throughout a single season using 2 orthogonal high-speed cameras at 120 Hz. The first fastball of each inning and, when available, the fastball subsequent to the 15th and 30th pitch of each inning were recorded and analyzed for 26 kinematic parameters. Pitch count and velocity were recorded. Kinematic differences were assessed for association with pitch count and subjective fatigue measures over the course of each inning and game through the season. RESULTS: Twenty-six games were recorded. Pitchers had a mean of 97.2 ± 16.1 pitches per start and 1079 ± 251 pitches per collegiate season. Increased hip lean at hand separation, elbow height at foot contact, and hip flexion and shoulder tilt at maximum external rotation were seen in innings lasting longer than 15 pitches. Maximum external rotation of the shoulder and elbow height at foot contact decreased over the course of a game. Hip lean at hand separation and elbow height at foot contact increased over the course of the season. Season pitch count was weakly correlated with increased shoulder external rotation and shoulder alignment at maximum external rotation and with shoulder abduction at ball release. Elbow flexion decreased with greater season pitch counts. CONCLUSION: Hip lean, elbow height, and shoulder external rotation were the most sensitive kinematic parameters to inning, game, and season fatigue. Pitch count and fatigue have a significant impact on live-game pitching kinematics. CLINICAL RELEVANCE: Fatigue likely alters pitching mechanics. Recognition of kinematic alterations may better demonstrate fatigue-related injury risk and may assist injury prevention in addition to standardized limitations of innings and pitches thrown.

Elbow arthroscopic surgery update for sports medicine conditions.

Elbow arthroscopic surgery can now effectively treat a variety of conditions that affect athletes. Advances in instrumentation, increased surgeon familiarity, and expanded indications have led to significant growth in elbow arthroscopic surgery in the past few decades. While positioning, portal placement, and specific instruments may vary among surgeons, anatomic considerations guide surgical approaches to minimize neurovascular compromise. Arthroscopic procedures vary in difficulty, and surgeons should follow stepwise advancement with experience. Removal of loose bodies, debridement of synovial plicae, and debridement of the extensor carpi radialis brevis for lateral epicondylitis are considered simple procedures for novice elbow arthroscopic surgeons. More advanced procedures include management of osteochondritis dissecans, valgus extension overload in the throwing athlete, and capsular release. With proper technique, a variety of athletic elbow conditions can be treated arthroscopically with predictable results and minimal morbidity.

Characterizing bone tunnel placement in medial ulnar collateral ligament reconstruction using patient-specific 3-dimensional computed tomography modeling.

BACKGROUND: Medial ulnar collateral ligament (MUCL) reconstruction is successful in restoring valgus elbow stability, but variability in bone tunnel characteristics exists among surgical techniques. HYPOTHESIS: Tunnel parameters such as diameter, drill angle, and starting location in MUCL reconstruction affect tunnel length and bone bridge size between tunnels. STUDY DESIGN: Descriptive laboratory study. METHODS: Three-dimensional models were created from elbow computed tomography scans of 10 throwing athletes and analyzed using Mimics (Materialise) software. The MUCL reconstructions were simulated on each elbow with 3 techniques: Jobe, humeral docking, and DANE TJ. Humeral central tunnels were modified by diameter, medial-lateral epicondylar starting point, and angle with respect to the humeral axis. Ulnar tunnels were varied by diameter and angle with respect to the ulnar axis. Humeral tunnel length, humeral and ulnar bone bridge sizes, and ulnar tunnel aperture and distance from the articular surface of the olecranon were measured. Comparisons were made using 1- and 2-way analysis of variance and Student-Newman-Keuls multiple comparison tests. RESULTS: Mean central humeral tunnel length varied significantly by starting point and angulation of the tunnel both in sagittal and coronal planes, ranging from 14.2 ± 2.3 mm to 25.5 ± 4.3 mm (P < .05). Mean bone bridge size between humeral exit tunnels ranged from 9.0 ± 2.5 mm to 15.1 ± 3.1 mm, varying by central humeral tunnel orientation and exit tunnel diameter (P < .05). Bone bridge size between ulnar tunnels with the Jobe and docking techniques averaged 6.7 ± 0.9 mm (3.2-mm tunnels) and 6.4 ± 0.8 mm (3.5-mm tunnels), respectively. Angle of ulnar tunnels affected distance from the articular surface with the Jobe and docking techniques (P < .0001) and affected tunnel aperture size with the interference screw technique (P < .0001). CONCLUSION: Humeral and ulnar tunnel angles, starting points, and diameters affect tunnel length, distance from the articular surface, and bone bridge size in MUCL reconstructions. Maximal humeral tunnel length is achieved by starting central or lateral to the midpoint of the epicondyle, angulated 30° to the humeral axis in the sagittal plane and 15° in the coronal plane. A reasonable goal tunnel depth should range from 15 to 20 mm. Ulnar tunnels should be placed on the anterior and posterior aspects of the sublime tubercle, directed away from the joint to minimize the likelihood of breaching the articular cartilage. A bone bridge of 6 to 8 mm between these tunnels can be reasonably achieved. Tunnels with the ulnar interference screw fixation technique should also be directed away from the joint but at an angle more perpendicular than 45° to minimize tunnel aperture size. Regardless of angle of the tunnel drilled for the ulnar interference screw employed in the DANE TJ technique, the tunnel length is sufficient to fully contain a 15-mm screw. CLINICAL RELEVANCE: Computer models can guide MUCL reconstruction technique by indicating tunnel placement for maximizing the bone bridge and tunnel length.

Radiographic outcomes of volar locked plating for distal radius fractures.

PURPOSE: To assess the ability of volar locked plating to achieve and maintain normal radiographic parameters for articular stepoff, volar tilt, radial inclination, ulnar variance, and radial height in distal radius fractures. METHODS: We performed a retrospective review of 185 distal radius fractures that underwent volar locked plating with a single plate design over a 5-year period. We reviewed radiographs and recorded measurements for volar tilt, radial inclination, ulnar variance, radial height, and articular stepoff. We used logistic regression to determine the association between return to radiographic standard norms and fracture type. RESULTS: At the first and final postoperative follow-up visits, we observed articular congruence less than 2 mm in 92% of fractures at both times. Normal volar tilt (11°) was restored in 46% at the first follow-up and 48% at the final one. Radial inclination (22°) was achieved in 44% at the first follow-up and 43% at the final one, and ulnar variance (01 ± 2 mm) was achieved in 53% at the first follow-up and 53% at the final one. In addition, radial height (14 ± 1mm) was restored in 14% at the first follow-up and 12% at the final one. More complex, intra-articular fractures (AO class B and C and Frykman types 3, 4, 7, and 8) were less likely to be restored to normal radiographic parameters. However, because of the small sample size for some fracture types, it was difficult to discover significant associations between fracture type and radiographic outcome. CONCLUSIONS: Volar locked plating for distal radius fractures achieved articular stepoff less than 2 mm in most fractures but only restored and maintained normal radiographic measurements for volar tilt, radial inclination, and ulnar variance in 50% of fractures. The ability of volar locked plating to restore and maintain ulnar variance and volar tilt decreased with more complex intra-articular fracture types. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

A primer for physical examination of the elbow.

The elbow is a complex joint consisting of 3 separate but important articulations: the ulnohumeral, radiohumeral, and proximal radioulnar joints. The elbow assists in positioning the hand in space through 2 important motions, flexion-extension and pronation-supination. Although the elbow is not a weightbearing joint, it is subjected to significant loads, especially in overhead and throwing athletes. An accurate knowledge of the anatomy and physiology of the elbow joint is critical for conducting a focused physical examination and arriving at an accurate diagnosis. The goal of this article is to review general and focused physical examination of the elbow in a systematic manner based on medial, lateral, anterior, and posterior aspects.

Humeral head abrasion: an association with failed superior labrum anterior posterior repairs.

HYPOTHESIS: An abrasion on the humeral head under the articulating portion of the biceps tendon has been observed in patients with pain and stiffness after superior labrum anterior posterior (SLAP) repair. This study examined this humeral head abrasion (HHA) and its association with various diagnoses involving pathology of the biceps-labral complex. We hypothesized that it would be more common in failed SLAP repairs than other diagnoses. MATERIALS AND METHODS: A retrospective chart review was performed of 253 patients who underwent shoulder arthroscopy by a single surgeon during a 5-year period. Postoperative diagnoses were used to confirm one of the following diagnoses: failed SLAP repair, biceps tendonitis, SLAP lesion with biceps tendonitis, and isolated SLAP lesion. Operative reports and surgical images were analyzed to identify the presence or absence of HHA. Demographic data, including age, sex, handedness, and onset of injury, were also collected. The frequency of this lesion among the different diagnoses and patient characteristics was compared by χ² analysis. RESULTS: HHA was observed in 13 of 18 patients (72.2%) with failed SLAP repairs, in 8 of 18 (44.4%) with biceps tendonitis, in 11 of 20 (55%) with SLAP lesion and biceps tendonitis, and in 1 of 71 (1.4%) with isolated SLAP lesions, significantly differing in frequency by diagnosis (P < .001). Patients with HHA were an older median age than those without (48 vs 40; P = .004). DISCUSSION: HHA is common in patients with a pathologic biceps-labral complex, especially those with failed SLAP repair. We speculate that this lesion is due to inflammation of the biceps tendon resulting in increased biceps-humeral head contact pressure.

Preseason shoulder strength measurements in professional baseball pitchers: identifying players at risk for injury.

BACKGROUND: The ability to identify pitchers at risk for injury could be valuable to a professional baseball organization. To our knowledge, there have been no prior studies examining the predictive value of preseason strength measurements. HYPOTHESIS: Preseason weakness of shoulder external rotators is associated with increased risk of in-season throwing-related injury in professional baseball pitchers. STUDY DESIGN: Cohort study (prognosis); Level of evidence, 2. METHODS: Preseason shoulder strength was measured for all pitchers in a professional baseball organization over a 5-year period (2001-2005). Prone internal rotation (IR), prone external rotation (PER), seated external rotation (SER), and supraspinatus (SS) strength were tested during spring training before each season. The players were then prospectively followed throughout the season for incidence of throwing-related injury. Injuries were categorized on an ordinal scale, with no injury, injury treated conservatively, and injury resulting in surgery delineated 0, 1, and 2, respectively. Subset analyses of shoulder injuries and of players with prior surgery were also performed. The association between strength measurements and injury was analyzed using Spearman rank correlation. RESULTS: A statistically significant association was observed for PER strength (P = .003), SER strength (P = .048), and SS strength (P = .006) with throwing-related injury requiring surgical intervention. Supraspinatus strength was also significantly associated with incidence of any shoulder injury (P = .031). There was an association between the ratio of PER/IR strength and incidence of shoulder injury (P = .037) and some evidence for an association with overall incidence of throwing-related injury (P = .051). No associations were noted in the subgroup of players with prior surgery. CONCLUSION: Preseason weakness of external rotation and SS strength is associated with in-season throwing-related injury resulting in surgical intervention in professional baseball pitchers. Thus, preseason strength data may help identify players at risk for injury and formulate strengthening plans for prevention.

Effects of wearing foot orthosis with medial arch support on the fifth metatarsal loading and ankle inversion angle in selected basketball tasks.

STUDY DESIGN: Preintervention and post-intervention, repeated-measures experimental design. OBJECTIVES: The objective was to investigate the effects of foot orthoses with medial arch support on ankle inversion angle and plantar forces and pressures on the fifth metatarsal during landing for a basketball lay-up and during the stance phase of a shuttle run. BACKGROUND: Proximal fractures of the fifth metatarsal, specifically the Jones fracture, are common in sports. Wearing foot orthoses with medial arch support could increase the ankle inversion angle and the plantar forces and pressure on the fifth metatarsal that may increase the risk for fifth metatarsal fracture, METHODS AND MEASURES: Three-dimensional (3-D) videographic, force plate, and in-shoe plantar force and pressure data were collected during landing after a basketball lay-up and during the stance phase of a shuttle run with and without foot orthoses with medial arch support for 14 male subjects. Two-way ANOVAs with repeated measures were performed to compare ankle inversion angle, maximum forces, and pressure on the fifth metatarsal head and base between conditions and between tasks. RESULTS: The maximum ankle inversion angle and maximum plantar force and pressure on the base of the fifth metatarsal during both tasks as well as the maximum plantar force and pressure on the head of the fifth metatarsal during the stance of the shuttle run were significantly increased (P< or =026) when wearing foot orthoses. No significant differences were found in the maximum vertical ground reaction forces between foot orthotic conditions. CONCLUSION: Generic use of off-the-shelf foot orthoses with medial arch support causes increased plantar forces and pressures on the fifth metatarsal and may increase the risk for proximal fracture of the fifth metatarsal. Future studies are needed to investigate this risk, acknowledging that the differences noted in our study were small in magnitude and the foot type was not measured.

The use of suture anchors in repair of the ruptured patellar tendon: a biomechanical study.

BACKGROUND: Rupture of the patellar tendon is a disabling injury that usually requires surgical treatment. The standard method of repair involves placing suture loops through transpatellar tunnels. The use of suture anchors in patellar tendon repair has not been previously described. HYPOTHESIS: No difference exists in the amount of gap formation during cyclic loading or in ultimate load-to-failure strength between repairs performed with anchors and those performed with 2 types of transpatellar sutures. STUDY DESIGN: Controlled laboratory study. METHODS: Six matched pairs of cadaveric knees were tested in a custom biomechanical apparatus based on an established model. Repairs were performed using either suture anchors with No. 2 FiberWire or transpatellar suture tunnels using 2 different types of suture-No. 5 Ethibond and No. 2 FiberWire. Gap formation across the repair site during 250 cycles of extension as well as ramp-up load to failure were measured for each repair. RESULTS: The mean total gap formation across the repair site at 250 cycles was 4.1 +/- 1.9 mm for the suture anchor group, 6.7 +/- 1.8 mm for the FiberWire tunnel group, and 8.5 +/- 2.7 mm for the Ethibond tunnel group. Mean load to failure was 779 +/- 183 N, 730 +/- 83 N, and 763 +/- 231 N, respectively. CONCLUSION: Significantly less gap formation throughout 250 cycles (P = .009) and no difference in load to failure occurred with patellar tendon repairs performed with suture anchors as compared with repairs performed with transpatellar tunnels. CLINICAL RELEVANCE: The newly described method, using suture anchors for repair of patellar tendon ruptures, may be clinically equal or superior to the established method of using transpatellar tunnels.