Thumb Metacarpophalangeal Joint Kinematics and Elongation of the Ulnar Collateral Ligament.

PURPOSE: The purpose of the study was to determine if the sphericity of the thumb metacarpophalangeal (MCP) joint influences the joint's rotational axis (RA) and elongation patterns of the ulnar collateral ligament (UCL). METHODS: Ulnar collateral ligament origins and attachments of 28 fresh-frozen cadaveric thumbs were marked with a radiopaque marker. Lateral radiographs were obtained in neutral and 20°, 40°, and 60° of flexion. The dorsal and palmar joint gap and the length of four different UCL portions were digitally measured in all flexion states. The RA was determined by the intersection of the midshaft axis of the proximal phalanx in neutral and flexion states. Sphericity of the MCP joint was assessed using morphometric parameters. Joints were grouped as round or flat. Differences in all measured parameters between groups were analyzed. RESULTS: During flexion, the dorsal joint gap increased by 322% in flat joints and 163% in round joints. The palmar joint gap decreased to 45% in flat joints and to 87% in round joints. The RA was at 29% of metacarpal height and 96% of metacarpal length in flat joints and at 40% of height and 86% of length in round joints. Maximum UCL elongation (111%) was noted at 40° flexion in the dorsal proper UCL in flat joints and at 60° flexion in the accessory UCL (117%) in round joints. CONCLUSIONS: In flat MCP joints, the RA is more dorsal and distal in the metacarpal head compared to round joints, resulting in a hinged flexion motion. Elongation of the UCL is highest at end flexion in round joints and highest at midflexion in flat joints. CLINICAL RELEVANCE: The different kinematics of flat and round MCP joints may contribute to the understanding of the pathophysiology of UCL ruptures. The propensity of this injury and the position in which they occur may be affected by the MCP joint morphology.

Characterizing focal muscle signal on MRI in flexor-pronator muscles' status post ulnar collateral ligament reconstruction.

OBJECTIVE: Focal high signal is commonly seen about the flexor pronator mass on MRI in some patients after ulnar collateral ligament (UCL) reconstruction of the elbow. The etiology of this high signal is unclear and not described in literature. The hypothesis is that the edema we see on post-operative MRI is related to palmaris longus graft harvest rather than secondary to other causes of muscle edema such as denervation or muscle strain. METHODS AND MATERIALS: An IRB waiver-approved, retrospective search of our radiology database was conducted using the keywords "ucl," "elbow," and "reconstruction" between 1/01/2012 and 1/01/2022, with search parameters set as MRI for exam type. The images were reviewed to evaluate for high signal at the flexor pronator mass by a junior and a senior musculoskeletal radiologist. The surgical notes were then reviewed in electronic medical record system to see which graft was used for the UCL reconstruction. RESULTS: The cohort comprised of 33 patients (1 female/32males, 14-51 years old) who had undergone UCL reconstructions. Four patients were excluded from the study secondary to the surgical note not specifying which graft was used. The surgical and imaging dates were also recorded with the largest time gap of 7 years between the surgery and imaging. Seventeen of the 29 patients had palmaris longus harvested from the ipsilateral arm, 1 patient had palmaris longus harvested from the contralateral arm, 2 patients had an internal brace, and 9 patients had a hamstring graft. Seventeen out of 17 (100%) patients with ipsilateral palmaris longus graft demonstrated focal edema at the flexor pronator mass while 0/12 of the patients without the palmaris longus graft showed the focal edema seen by its counterparts. CONCLUSION: High signal which is commonly seen at the flexor pronator mass in patient status most UCL reconstruction of the elbow is secondary to the palmaris longus harvest rather than other etiologies such as muscle strain, retear, or trauma.

Elbow Ulnar Collateral Ligament Tears in 2023: Evaluation and Management.

The ulnar collateral ligament, also called the medial collateral ligament of the elbow, is the primary stabilizer against valgus loads. This ligament can be traumatically torn, such as in an elbow dislocation, or can tear through attritional damage with overhead sports. Although baseball pitching is the most common contributor, these injuries also occur with volleyball, gymnastics, and javelin throwing. Patients most commonly report a history of medial elbow pain with associated loss of command, control, and throw velocity. The ulnar nerve lies directly superficial to the posterior band of the ulnar collateral ligament and ulnar neuritis is commonly associated with ulnar collateral ligament pathology. Nonsurgical treatment, including rest from activity, flexor-pronator strengthening, and possible platelet-rich plasma injections, can be considered for partial-thickness tears. Surgical treatment can be considered for patients in whom nonsurgical treatment fails and full-thickness tears. Historically, surgical treatment involved reconstruction of the ligament with a tendon graft. Ipsilateral palmaris longus autograft has been the most commonly used graft, but contralateral palmaris, autograft hamstring tendons, and allograft tendon have also been used. This procedure has a high rate of return to play and a low complication rate, but most athletes require 12 to 18 months to fully return. More recently, repair of the ligament, with the addition of a biologic ingrowth ligament augmentation suture, has demonstrated similarly high rates of return to play and low complication rates, with a full return to play in 6 months.

Surgical Interventions for Chronic Ulnar Collateral Ligament Injuries of the Thumb: A Systematic Review.

Background: There is no consensus for the appropriate surgical management of symptomatic chronic ulnar collateral ligament (UCL) injuries of the thumb. The aim of this study is to systematically review the treatment of chronic thumb metacarpophalangeal (MCP) joint UCL injuries to determine the optimal approach to treatment. Methods: A systematic review of PubMed, Medline, Embase and ePub Ahead of Print was performed in accordance with Preferred Reporting of Items in Systematic Review and Meta-Analysis (PRISMA) guidelines. Results: Data from 11 studies using various surgical techniques in 245 thumbs were heterogenous and meta-analysis of results not possible. These data were qualitatively assessed. Direct repair, reconstruction with free tendon grafts and arthrodesis all demonstrated favourable outcomes with patient-reported outcome measures (PROMs). Conclusions: Direct repair can be safely performed more than 2 months following injury. Arthrodesis may be considered in heavy manual labourers or those with osteoarthrosis. Tendon grafting is safe, yet the optimal type and configuration are yet to be determined for reconstructive methods. Level of Evidence: Level III (Therapeutic).

Posterolateral Rotatory Instability Develops Following the Modified Kocher Approach and Does Not Resolve Following Interval Repair.

BACKGROUND: The modified Kocher and extensor digitorum communis (EDC)-splitting intervals are commonly utilized to approach the lateral elbow. Iatrogenic injury to the lateral ulnar collateral ligament may result in posterolateral rotatory instability (PLRI). in the present cadaveric study, we (1) evaluated lateral elbow stability following the use of these approaches and (2) assessed the accuracy of static lateral elbow radiographs as a diagnostic tool for PLRI. METHODS: Ten matched-pair cadaveric upper-extremity specimens (n = 20) were randomly assigned to Kocher or EDC-splitting approaches. Specimens underwent evaluation pre-dissection, post-dissection, and following repair of the surgical interval. Clinical evaluation of lateral elbow stability was performed with the lateral pivot-shift maneuver. Radiographic radiocapitellar displacement was evaluated with the fully extended hanging arm test and on lateral elbow 30° flexion radiographs. Paired Wilcoxon signed-rank tests with Bonferroni correction were utilized to compare groups. RESULTS: All Kocher group specimens (10 of 10) developed PLRI on the pivot-shift maneuver following dissection. No EDC-splitting group specimens (0 of 10) developed instability with pivot-shift testing. The fully extended hanging arm test showed no difference in radiocapitellar displacement between groups (p > 0.008). Lateral elbow 30° flexion radiographs in the Kocher group showed an increased radiocapitellar displacement difference (mean, 8.46 mm) following dissection compared with the pre-dissection baseline (p < 0.008). Following repair of the Kocher interval, the radiocapitellar displacement (mean, 6.43 mm) remained greater than pre-dissection (mean, 2.26 mm; p < 0.008). In the EDC-splitting group, no differences were detected in radiocapitellar displacement on lateral elbow radiographs with either the fully extended hanging arm or lateral elbow 30° flexion positions. CONCLUSIONS: The Kocher approach produced PLRI that did not return to baseline conditions following repair of the surgical interval. The EDC-splitting approach did not cause elbow instability clinically or radiographically. The hanging arm test was not reliable for the detection of PLRI. CLINICAL RELEVANCE: The Kocher interval for lateral elbow exposure results in iatrogenic PLRI that is not detectable on the hanging arm test and that does not return to baseline stability following repair of the surgical interval.

Conservative Approach to Treating American Football Players With Medial Collateral Ligament Grade 2 Sprain During the Season.

CONTEXT: The medial collateral ligament is the most commonly injured ligament in the knee. The high-speed pivoting and agility movements that are common in the sport of American Football put participants at an increased risk for a valgus force stress from contact or noncontact injuries. Positional release therapy (PRT) also considered strain/counterstrain focuses on releasing the tension in a tissue through unloading the involved body part. CASE PRESENTATION: Two male student-athletes participating in football with a mean age of 20.5 years were diagnosed by a physician with medial collateral ligament grade 2 sprain. Both patients sustained their injuries in a regular season game with a contact valgus force from an opposing player. MANAGEMENT AND OUTCOMES: After the initial 72 hours of compression, elevation, and cryotherapy, the patients were both treated with PRT followed by progressive loading exercises. Following 4 treatment sessions of PRT over the next 6 days, the patients started with quadriceps engagement exercises, single-leg squats to 60° knee flexion, side steps, triceps dips, slow controlled lunges, and toe walk. The patients progressed to full body weight squats, single-leg landing, step-up tri-extension, and sidekicks with a leg on table. Then, the patients completed function movements and sports-specific exercises. CONCLUSIONS: In this case series, 2 patients competing in intercollege American Football were treated with PRT and progressive loading exercises to facilitate return to unrestricted activities and improve outcome measures. Commonly, a grade 2 medial collateral ligament sprain is conservatively treated with return to sport taking 20 days on average. In this type 2 case series, the clinician found success utilizing PRT early in the recovery process, which in these 2 cases lead to restoration of function, outcome measure improvement, and an expedited return to sport. The expedited return to sport occurred at an average of 18 days for these patients.

An isolated rupture of the anterolateral ligament of the knee: A case report.

INTRODUCTION: The anterolateral ligament (ALL) is a controversial ligament in the knee that may play a significant role in knee stability. It is difficult to identify on magnetic resonance imaging (MRI) imaging and is often injured in conjunction with other ligaments, such as the anterior cruciate ligament (ACL) and medial collateral ligament. CASE PRESENTATION: This is a unique case of an isolated ALL tear in a 48-year-old woman who presented with severe left knee pain, swelling, and inability to bear weight during a yoga session. Physical examination showed swelling and tenderness at the lateral aspect of the femoral condyle, with increased pain on varus stress testing. Radiographs revealed normal osseous structures with the absence of traumatic bone lesions. MRI revealed an intact meniscus, cruciate, and collateral ligaments, but a rupture of the ALL at its femoral origin. Diagnosis of isolated ALL rupture of the left knee was made, and the patient was treated conservatively with icing, rest, and non-steroidal anti-inflammatory drugs. Physiotherapy was started 2 weeks post-injury, and return to sports was allowed at the sixth week. Upon last follow-up, the patient had excellent functional outcomes and was satisfied with the treatment. Physical examination showed a stable knee with negative Lachman and pivot shift tests. To the best of the authors' knowledge, this is the first case of isolated ALL rupture to be reported. DISCUSSION: The paper highlights the rarity of isolated ALL injuries and the difficulty in diagnosing them. Conservative treatment can be successful for isolated ALL injuries, with physiotherapy playing an essential role in rehabilitation.In conclusion, isolated ALL injuries are rare and can be challenging to diagnose. Conservative treatment with physiotherapy can lead to successful outcomes. Further research is needed to understand the role of the ALL in knee stability and to determine optimal treatment options.

Implant-free anatomical reconstruction of thumb metacarpophalangeal joint chronic ulnar collateral ligament injuries.

A technique is described to treat chronic instability of the metacarpophalangeal joint of the thumb caused by rupture of the ulnar collateral ligament using a palmaris longus tendon graft without implants. Good results were obtained in eight patients.

Acute Thumb Metacarpophalangeal Joint Ulnar Collateral Ligament Injury: Diagnosis, Management, and Return to Sports Considerations.

ABSTRACT: Thumb metacarpophalangeal joint ulnar collateral ligament injuries are common in athletes and range from mild sprains to complete retracted tears. The typical injury mechanism of a valgus force directed onto an abducted or extended thumb is frequently seen in certain sporting activities, such as skiing, football, and baseball. Ultrasound and magnetic resonance imaging are excellent imaging supplements to the clinical evaluation for diagnosis confirmation. Positive treatment outcomes have been demonstrated when these injuries are appropriately managed both nonoperatively and surgically. When deciding on a treatment plan, it is paramount to take the athlete's injury severity and sport-specific factors into account. The aim of this review is to summarize the sport epidemiology, diagnosis, treatment options, and return to play considerations for athletes who sustain an acute thumb metacarpophalangeal joint ulnar collateral ligament injury.

Patient-Reported Outcomes and Function After Surgical Repair of the Ulnar Collateral Ligament of the Thumb.

PURPOSE: The purpose of this study was to report prospectively collected patient-reported outcomes of patients who underwent open thumb ulnar collateral ligament (UCL) repair and to find risk factors associated with poor patient-reported outcomes. METHODS: Patients undergoing open surgical repair for a complete thumb UCL rupture were included between December 2011 and February 2021. Michigan Hand Outcomes Questionnaire (MHQ) total scores at baseline were compared to MHQ total scores at three and 12 months after surgery. Associations between the 12-month MHQ total score and several variables (i.e., sex, injury to surgery time, K-wire immobilization) were analyzed. RESULTS: Seventy-six patients were included. From baseline to three and 12 months after surgery, patients improved significantly with a mean MHQ total score of 65 (standard deviation [SD] 15) to 78 (SD 14) and 87 (SD 12), respectively. We did not find any differences in outcomes between patients who underwent surgery in the acute (<3 weeks) setting compared to a delayed setting (<6 months). CONCLUSIONS: We found that patient-reported outcomes improve significantly at three and 12 months after open surgical repair of the thumb UCL compared to baseline. We did not find an association between injury to surgery time and lower MHQ total scores. This suggests that acute repair for full-thickness UCL tears might not always be necessary. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic II.

Increased signal of the fibular collateral ligament of the knee on MRI, clinically significant?

INTRODUCTION: The purpose of this study was to determine the clinical significance of signal hyperintensity in the proximal fibular collateral ligament (FCL) on coronal proton density (PD) fat-saturated (FS) MRI of the knee, a common finding. This study is unique in that it characterizes the FCL of a comprehensive, large cohort of both symptomatic and asymptomatic patients, which to our knowledge represents the first study with such broad inclusion criteria. METHODS: A large case series was performed analyzing MRI of the knee of 250 patients from July 2021 through September 2021 and retrospectively reviewed. All studies were performed on 3-Tesla MRI scanners with a dedicated knee coil and in accordance with standard institutional knee MRI protocol. Signal in the proximal fibular collateral ligament was assessed on coronal PDFS and axial T2-weighted FS images. Increased signal was classified as none, mild, moderate, or severe. A corresponding chart review of clinic notes was performed to determine the presence or absence of lateral knee pain. An FCL sprain or injury was considered present if the medical record described tenderness on palpation of the lateral knee, positive finding against resistance to the leg (varus stress test) or reverse pivot shift, or any clinical suspicion for lateral complex sprain or posterolateral corner injury. RESULTS: The majority (74%) of knee MRIs demonstrated the presence of increased signal in the proximal fibular collateral ligament on coronal PD FS images. <5% of these patients had associated clinical findings of fibular collateral ligament and/or lateral supporting structure injury. DISCUSSION: Although increased signal in the proximal FCL of the knee is a common finding on coronal PDFS images, the majority are not associated with clinical symptoms. Thus, this increased signal is likely not a pathological finding in the absence of clinical findings of fibular collateral ligament sprain/injury. Our study emphasizes the importance of clinical correlation in identifying increased signal in the proximal FCL as pathologic.

2022 Bernard Morrey Award: the elbow ulnar collateral ligament complex demonstrates region specific stretching and recovery characteristics with valgus loading.

BACKGROUND: The objective of this study was to quantify the valgus laxity and strain of the elbow ulnar collateral ligament (UCL) complex after repeated valgus stretching and subsequent recovery. Understanding these changes may have important implications in improving strategies for injury prevention and treatment. The hypothesis was that the UCL complex will demonstrate a permanent increase in valgus laxity and region-specific increase in strain as well as region-specific recovery characteristics. METHODS: Ten cadaveric elbows (7M, 3F, 61.7 ± 2.7 years) were used. Valgus angle and strain of the anterior and posterior bands of the anterior bundle and the posterior bundle were measured at 1 Nm, 2.5 Nm, 5 Nm, 7.5 Nm, and 10 Nm of valgus torque at 70° of flexion for: (1) intact UCL, (2) stretched UCL, and (3) rested UCL. To stretch the UCL, elbows were cycled with increasing valgus torque at 70° of flexion (10 Nm-20 Nm in 1 Nm increments) until the valgus angle increased 8° from the intact valgus angle measured at 1Nm. This position was held for 30 minutes. Specimens were then unloaded and rested for 2 hours. Linear mixed effects model with Tukey's post hoc test was used for statistical analysis. RESULTS: Stretching significantly increased valgus angle compared to the intact condition 3.2° ± 0.2° (P < .001). Strains of both the anterior and posterior bands of the anterior bundle were significantly increased from intact by 2.8% ± 0.9% (P = .015) and 3.1% ± 0.9% (P = .018), respectively at 10 Nm. Strain in the distal segment of the anterior band was significantly higher than the proximal segment with loads of 5 Nm and higher (P < .030). After resting, the valgus angle significantly decreased from the stretched condition by 1.0° ± 0.1° (P < .001) but failed to recover to intact levels (P < .004). After resting, the posterior band had a significantly increased strain compared to the intact state of 2.6% ± 1.4% (P = .049) while the anterior band was not significantly different from intact. CONCLUSION: After repeated valgus loading and subsequent resting, the UCL complex demonstrated permanent stretching with some recovery but not to intact levels. The anterior band demonstrated increased strain in the distal segment compared to the proximal segment with valgus loading. The anterior band was able to recover to strain levels similar to intact after resting, while the posterior band did not.

Elbow Ulnar Collateral Ligament Tears: A Modified Consensus Statement.

PURPOSE: To establish consensus statements on the treatment of ulnar collateral ligament (UCL) injuries and to investigate whether consensus on these distinct topics could be reached. METHODS: A modified consensus technique was conducted among 26 elbow surgeons and 3 physical therapists/athletic trainers. Strong consensus was defined as 90% to 99% agreement. RESULTS: Of the 19 total questions and consensus statements 4 achieved unanimous consensus, 13 achieved strong consensus, and 2 did not achieve consensus. CONCLUSIONS: There was unanimous agreement that the risk factors include overuse, high velocity, poor mechanics, and previous injury. There was unanimous agreement that advanced imaging in the form of either magnetic resonance imaging or magnetic resonance arthroscopy should be performed in a patient presenting with suspected/known UCL tear that plans to continue to play an overhead sport, or if the imaging study could change the management of the patient. There was unanimous agreement regarding lack of evidence for the use of orthobiologics in the treatment of UCL tears as well as the areas pitchers should focus on when attempting a course of nonoperative management. The statements that reached unanimous agreement for operative management were regarding operative indications and contraindications for UCL tears, prognostic factors that should be taken into consideration in when performing UCL surgery, how to deal with the flexor-pronator mass during UCL surgery, and use of an internal brace with UCL repairs. Statements that reached unanimous agreement for return to sport (RTS) were regarding portions of the physical examination should be considered when determining whether to allow a player to RTS; unclear how velocity, accuracy, and spin rate should be factored into the decision of when players can RTS and sports psychology testing should be used to determine whether a player is ready to RTS. LEVEL OF EVIDENCE: V, expert opinion.

Finger Metacarpophalangeal Joint Injuries in Athletes: Evaluation, Diagnosis, Treatment, and Return to Play.

Metacarpophalangeal (MCP) joint injuries of the fingers are frequent among athletes and can markedly affect an athlete's ability to perform at a high level. Despite this, MCP finger injuries in athletes are not frequently discussed, particularly in comparison with MCP joint injuries of the thumb, and remain unrecognized and undertreated injuries in this cohort. Accurate diagnosis and treatment of these injuries begins with an understanding of all the potential diagnoses. The purpose of this study was to review the pertinent anatomy and differential diagnoses for MCP joint injuries in athletes, including the evaluation and management to allow for safe and early return to play.

Epidemiology of Lateral Ligament Complex Tears of the Ankle in National Collegiate Athletic Association (NCAA) Sports: 2014-15 Through 2018-19.

BACKGROUND: Epidemiological studies of lateral ankle sprains in NCAA sports are important in appraising the burden of this injury and informing prevention efforts. PURPOSE: To describe the epidemiology of lateral ankle sprains in NCAA sports during the 2014-15 through 2018-19 seasons. STUDY DESIGN: Descriptive epidemiology study. METHODS: Injury and exposure information collected within the NCAA Injury Surveillance Program (ISP) were examined. Counts, rates, and proportions of lateral ankle sprains were used to describe injury incidence by sport, event type (practices, competitions), season segment (preseason, regular season, postseason), injury mechanism (player contact, noncontact, and surface contact, injury history (new, recurrent), and time loss (time loss [≥1 day], non-time loss). Injury rate ratios (IRRs) were used to examine differential injury rates, and injury proportion ratios (IPRs) were used to examine differential distributions. RESULTS: A total of 3910 lateral ankle sprains were reported (4.61 per 10,000 athlete exposures) during the study period, and the overall rate was highest in men's basketball (11.82 per 10,000 athlete exposures). The competition-related injury rate was higher than the practice-related rate (IRR, 3.24; 95% CI, 3.04-3.45), and across season segments, the overall rate was highest in preseason (4.99 per 10,000 athlete exposures). Lateral ankle sprains were most often attributed to player-contact mechanisms in men's (43.2%) and women's sports (35.1%), although injuries were more prevalently attributed to player contact in men's than in women's sports (IPR, 1.23; 95% CI, 1.13-1.34). Overall, 49.7% of all lateral ankle sprains were time loss injuries. CONCLUSIONS: The findings of this study are consistent with previous epidemiological investigations of lateral ankle sprains among NCAA athletes. Results offer additional context on differential injury mechanisms between men's and women's sports and on injury risk across the competitive season. Future research may examine the effectiveness of deploying injury prevention programs before the start of a season.

Can we do it faster? accelerated rehabilitation following thumb ulnar collateral ligament repair with suture tape augmentation.

Ulnar Collateral Ligament (UCL) injuries are the most common thumb metacarpophalangeal joint ligamentinjury. Rehabilitation protocols traditionally permit return to sport at 12 weeks post-surgery. In this article, we propose anacellerated rehabilitation protocol permitting return to sport at 5-6 post-surgery in the recreational athlete.

High-definition magnetic resonance images on medial elbow injuries in preadolescent Little Leaguers.

BACKGROUND: The incidence of throwing-related elbow injuries is still rising. The study aimed to enhance the pathology of acute medial elbow injuries among young Little Leaguers by examining the medial elbows of symptomatic 9-10 years old Little Leaguers using High-Definition Magnetic Resonance Images (HDMRI), which uses a small-diameter surface coil on the target area, leading to greater image resolution. METHOD: We identified Little Leaguers aged 9-10 years old. To minimize the detection of the chronic adaptative changes, players who experienced the medial elbow pain previously and whose HDMRI had not been taken within 4 weeks from the onset of medial elbow pain were excluded. This study considered 21 players, and the mean age was 9.4 ± 0.5 years. RESULT: The fragmentation of the medial epicondyle apophysis via HDMRI was found in 15 elbows (71.4%), while the avulsion was seen in three cases. The signal hyperintensity at the medial epicondyle apophysis was observed in 2 cases. Our data showed abnormal changes to the medial epicondyle apophysis and surrounding structures, such as the ulnar collateral ligament (UCL), flexor-pronator tendons or the coronoid process of the ulna. We detected 11 abnormalities on X-ray imaging, while 20 subjects showed some abnormal findings via HDMRI. DISCUSSION: The current study showed that initial medial elbow injury in Little Leaguers without a history of previous elbow injury could be attributed to multi-structure injury. Over 90% of subjects were injured in the perichondrium, while 71.4% demonstrated a fragmentation of the secondary ossification center, and 14.3% experienced an avulsion of the medial epicondyle apophysis. Because the injuries were not limited to bony structures, HDMRI may be beneficial for the appropriate evaluation of medial elbow pain. The pathology of initial medial elbow injuries in young baseball players may be due to acute trauma instead of repetitive microtrauma.

Locking suture repair versus ligament augmentation-a biomechanical study regarding the treatment of acute lateral collateral ligament injuries of the elbow.

BACKGROUND: Lateral collateral ligament (LCL) tears are frequently observed in fractures and dislocations of the elbow. Recent biomechanical evidence suggests that additional ligament augmentation may improve repair stability. The aim of this biomechanical in-vitro study was to compare the resistance of a locking suture repair of the LCL with a ligament augmentation technique. MATERIAL AND METHODS: Eight fresh frozen cadaveric elbows were evaluated for stability against varus/posterolateral rotatory forces (3 Nm). A strain gauge (µm/m; negative values) was placed at the origin and insertion of the lateral ulnar collateral ligament (LUCL) and cyclic loading was performed for 1000 cycles. We analyzed three distinct scenarios: (A) native LCL, (B) locking transosseou suture repair of the LCL, (C) simple LCL repair with additional ligament augmentation of the LUCL. RESULTS: The mean measured strain was - 416.1 µm/m (A), - 618 µm/m (B) and - 288.5 µm/m (C) with the elbow flexion at 90°; the strain was significantly higher in scenario B compared to C (p = .01). During the cyclic load (1000) the mean measured strain was - 523.1 µm/m (B) and - 226.3 µm/m (C) with the elbow flexion at 60°; the strain was significantly higher in scenario B compared to C (p = .01). No significant difference between the first and the last cycles was observed (p = .09; p = .07). One failure of the LCL repair was observed after 1000 cycles; none of the ligament augmentations failed. CONCLUSION: Ligament augmentation (C) provides higher resistance compared to the native LCL (A) and to the locking suture repair technique (B). Both techniques, however, hold up during 1000 cycles. While ligament augmentation might enhance the primary stability of the repair, future clinical studies have to show whether this increase in resistance leads to negative effects like higher rates of posttraumatic elbow stiffness. LEVEL OF EVIDENCE: Basic science study, biomechanics.

Thumb Metacarpophalangeal Joint Ulnar Collateral Ligament Injuries: Management and Biomechanical Evaluation.

First described in 1955 as "gamekeeper's thumb," injuries to the ulnar collateral ligament (UCL) of the thumb metacarpophalangeal joint are common and can cause pain and instability, especially during key pinch and grasp. Although primarily diagnosed on physical examination, stress radiographs, ultrasonography, and magnetic resonance imaging can be used to diagnose UCL injuries and distinguish partial from complete tears. If complete rupture occurs, the adductor aponeurosis can become interposed between the retracted UCL stump and its insertion on the proximal phalanx, known as a "Stener lesion." When instability persists after a trial of nonsurgical management or in the setting of complete rupture, there are various methods of repair or reconstruction. Biomechanically, there are no treatments of repair or reconstruction using native tissues that provide equivalent strength to the preinjured ligament. Recently, suture tape augmentation has been used for the repair or reconstruction with excellent short-term results and earlier return to function, although there is a paucity of literature on longer term outcomes. The various methods of surgical treatment yield excellent outcomes with a low incidence of complications.