Elbow Biomechanics: Bony and Dynamic Stabilizers

Outcomes and performance following posteromedial elbow débridement in Major League Baseball players

BACKGROUND

Overhead athletes are particularly susceptible to elbow valgus extension overload syndrome and development of pathologic changes in the posteromedial elbow. Though arthroscopic débridement/osteophyte resection is frequently performed, few studies have analyzed the outcomes of this procedure and none have specifically addressed professional level athletes.

HYPOTHESIS

We hypothesized that following posteromedial elbow débridement, Major League Baseball (MLB) pitchers would exhibit a higher rate of ulnar collateral ligament (UCL) reconstruction than baseline incidence in the existing literature, along with a decline in pitching performance.

METHODS

Using publicly accessible websites, MLB athletes undergoing posteromedial elbow débridement from 2007 to 2022 were identified. Demographic information, procedure details, return to play (RTP) information, return to the disabled/injured list (DL/IL), subsequent UCL reconstruction, and pitching statistics were analyzed. Pitching performance metrics included earned runs average, walks plus hits per innings pitched, innings pitched, and fastball velocity.

RESULTS

A total of 39 MLB players, including 26 pitchers, were included. Within the first three seasons after surgery, 82.1% (n = 32) of players returned to play at the MLB level at a mean time of 176.1 ± 69 days. Pitchers exhibited a RTP rate of 76.9% (n = 20) at 175.8 ± 16 days. A total of 38.5% (n = 10) of pitchers returned to the DL/IL for elbow-related issues within three seasons. Subsequent UCL reconstruction was seen only in pitchers, with a frequency of 19.2% (n = 5). No statistically significant differences between single season preoperative/postoperative pitching metrics were identified. A small but significant (P < .05) decrease in fastball velocity (94.4 vs. 92.84; P = .02) was observed over a three-season comparison.

CONCLUSION

Contrary to our hypothesis, this study demonstrates that posteromedial elbow débridement is a viable surgery in MLB athletes, with RTP rate of 82.1% and no increase in rate of UCL reconstruction. Furthermore, there was no significant difference in single season preoperative and postoperative statistical pitching performance. However, over three years postoperatively, there was a 38.5% rate of return to the DL/IL for ongoing elbow ailment and a significant decrease in pitch velocity, raising some concern over the longevity of postoperative improvements.

Clinical outcomes for linked fixation of distal humerus fractures: a multicenter study

BACKGROUND

O'Driscoll popularized the principle of linked column fixation for distal humerus fractures. Despite the linked column concept being widely accepted, there are few reported techniques to accomplish this goal. A novel device was designed based on the principles of linked columns. An interlocking beam is used to connect the medial and lateral plates, creating a unified fixed angle construct. Our primary objective was to report clinical outcomes across multiple institutions for a linking beam used in distal humerus fracture fixation.

METHODS

A retrospective series was collected from 5 institutions for the TiBeam (Skeletal Dynamics) with a minimum follow-up of 6 months. Acute and chronic treatment of distal humerus fracture patterns and all plate configurations were included for analysis.

RESULTS

A total of 36 cases were collected at a mean age of 52 years and a mean follow-up of 19.3 months. AO C-type fractures were 56% of the series. The median Mayo Elbow Performance Score was 85 (interquartile range [IQR] 76.3-90), the median DASH was 21.4 (IQR 15.9-30), and the median score on the visual analog scale for pain during activities of daily living was 3.5 (IQR 2-5). An olecranon osteotomy was used in 86% of cases, and an anatomic plate was used for fixation of the osteotomy in 94% of those cases. There were 3 cases of olecranon plate removal for a rate across the series of 13.7%.

DISCUSSION

Our short-term results demonstrate satisfactory clinical outcomes with low rates of revision for distal humerus fracture fixed with a linking beam. Further, the rate of removal for the olecranon osteotomy plate was lower than historical reports for aggregate methods of osteotomy fixation.

Proximal radioulnar joint, but not posterolateral, instability in patients with symptomatic minor instability of the lateral elbow

BACKGROUND

The elbow joint is stabilized laterally by a complex of bony and ligamentous structures, such as the lateral ulnar collateral ligament and radial lateral collateral ligament (RLCL). Pathogenesis of many elbow conditions like symptomatic minor instability of the lateral elbow (SMILE) is based on ligamentous incompetency. The aim of this study is to measure ligament elongation in SMILE patients and determine the correlation with the development of this pathologic condition.

MATERIALS AND METHODS

Twenty-eight patients were included in this study: half of them were operated for suspected SMILE whereas the others were affected by other elbow diseases. All the patients underwent elbow arthroscopy. During this procedure, 4 parameters were analyzed: annular drive through (ADT), ulnar-humeral stressed distance (UHSD) at 45° and 30° of flexion, and loose collar sign (LCS). A dedicated arthroscopic mini-spreader introduced through an arthroscopic portal was used to take measurements.

RESULTS

Statistically significant differences were found for LCS (P = .0003) and ADT (P = .000002). UHSD at 30° and 45° elbow flexion was slightly higher in SMILE patients, but not significantly.

DISCUSSION AND CONCLUSIONS

Progressive stretching of the RLCL and annular ligament may lead to their elongation, resulting in a pathologic anteroposterior shifting of the radial head and a lower congruence between the inner surface of the annular ligament and the radial head cartilage, resulting in proximal radioulnar instability. The study shows how RLCL and annular ligament are elongated in SMILE patients compared with controls, causing instability of the proximal radioulnar joint and confirming that ligament incompetency is involved in the SMILE condition.

An Ergonomic Golf Grip Leads to Lower Forearm Muscle Activity - A Prospective Case Series of 30 Right-Handed Amateur and Professional Golfers

BACKGROUND

The elbow is a common site for overuse injuries in golfers. Tendinopathies, such as medial and lateral epicondylitis, are frequently diagnosed in amateur and professional golfers. The aim of our study was to determine the effect of an ergonomic golf grip on forearm muscle activity during the five phases of the golf swing.

METHODS

Thirty right-handed golfers with a mean age of 32 years (range, 18-70 years) and a mean handicap of 15 (range, 0-43) performed 10 golf swings with a standard and ergonomic golf grip respectively. The mean and maximum muscle activity of the Musculus (M.) extensor carpi radialis brevis (ECRB), M. flexor carpi ulnaris (FCU), M. pronator teres (PT) and M. biceps brachii (BB) of the lead and trail arms were assessed during the five phases of the golf swing using surface electromyography (EMG). Subgroup analyses were performed regarding sex, playing ability (handicap < 10 vs. ≥10), weekly playing time (≤ 5 h, 5-20 h, > 20 h) and preexisting elbow pain during golfing (VAS < 2 vs. VAS ≥ 2). Significance was set at p < 0.05.

RESULTS

An ergonomic golf grip resulted in a reduction in muscle activity in at least one but up to three consecutive phases of the golf swing for the ECRB, FCU and PT of the lead arm and for the PT of the trail arm. Amateurs, a playing time < 20 h per week and golfers without preexisting elbow pain were factors that were associated with greater reductions in muscle activity.

CONCLUSION

Forearm muscle activity can be decreased using an ergonomic golf grip, indicating the possible role of an ergonomic golf grip as a preventive measure against overuse syndromes such as medial and lateral epicondylitis.

TRIAL REGISTRATION NUMBER

This study was retrospectively registered at the German Clinical Trials Register DRKS-ID: DRKS00033732 (01/03/2024).

Examining the changes in strength and mechanical property of dynamic stabilizers of the medial elbow joint through repetitive pitching

BACKGROUND

The flexor-pronator muscles (FPM) and their common tendon (CT) are essential in protecting the medial ulnar collateral ligament against elbow valgus stress during pitching. This study aimed to investigate the effect of repetitive pitching on FPM strength and CT stiffness.

METHODS

Fifteen healthy males (mean age: 21.8 ± 1.3 years old) with over 5 years of baseball experience performed a series of 100 full-effort fastball pitches. We measured grip and isolated digital flexion strength of the second, third, and fourth digits before and after the pitching task. The decline in muscle strength was determined using the rate of change in muscle strength after pitching relative to that before. CT stiffness was measured using a hand-held myotonometer device at rest and during grip motion at 50% maximum voluntary contraction. The increase in CT stiffness during grip motion relative to rest was calculated as the augmentation rate of CT stiffness. Statistical analyses were performed to compare the changes in grip strength, digital flexion strength, and CT stiffness due to pitching. Additionally, the reduction rate of muscle strength was compared among various strength variables. Correlation coefficients were used to evaluate the relationships between the augmentation rate of CT stiffness after pitching and the reduction rate in any muscle strength.

RESULTS

Grip and isolated digital flexion strengths decreased significantly after pitching (P < .01). The decline in muscle strength was significantly higher for all isolated digital strengths than that for grip strength (P < .05). CT stiffness was augmented with grip motion compared to that at rest pre- and postpitching (P < .001). However, no change in CT stiffness due to pitching was observed, regardless of the grip motion (P > .05). Additionally, a lower augmentation rate of CT stiffness after pitching was moderately associated with the greater reduction rate of the second digital flexion strength (r = 0.607, P = .016) without other relationships.

CONCLUSION

This study found reduced grip and digital flexion strength after pitching; with no change in CT stiffness. However, given the consequences of correlation analyses, individuals with a more prominent reduction in second digital flexion strength due to pitching were impaired in CT stiffness augmentation after pitching. Digital flexion strength represents the strength of the flexor digitorum superficial; therefore, this study suggests that forearm FPM, particularly the second digit of the flexor digitorum superficial, is an important factor for enhancing CT stiffness.

Complex Elbow Fracture-Dislocations: An Algorithmic Approach to Treatment

Elbow stability arises from a combination of bony congruity, static ligamentous and capsular restraints, and dynamic muscular activation. Elbow trauma can disrupt these static and dynamic stabilizers leading to predictable patterns of instability; these patterns are dependent on the mechanism of injury and a progressive failure of anatomic structures. An algorithmic approach to the diagnosis and treatment of complex elbow fracture-dislocation injuries can improve the diagnostic assessment and reconstruction of the bony and ligamentous restraints to restore a stable and functional elbow. Achieving optimal outcomes requires a comprehensive understanding of pertinent local and regional anatomy, the altered mechanics associated with elbow injury, versatility in surgical approaches and fixation methods, and a strategic rehabilitation plan.

A 70° Arthroscope Provides Better Visualization of the Medial Side of the Elbow Than a 30° Arthroscope

Purpose

To assess and quantify the improvement in visualization of humeral insertion of the medial collateral ligament (MCL) using a 70° scope compared with a 30° scope during elbow arthroscopy.

Methods

Twenty patients undergoing elbow arthroscopy for different pathologic conditions were enrolled in this single-center study. Visualization of the medial gutter of the elbow was evaluated by using both the 70° and the 30°scope. During the procedure, a needle was inserted at 45° with respect to the axis of the forearm, directed toward the intra-articular humeral emergence of the MCL. Four areas were established: the body (Z1), the lanceolate part (Z2), the tip of the needle (Z3), and the medial portion of the trochlea (Z4). The visible areas during arthroscopy using 2 different scopes were collected.

Results

The 70° scope allowed the detection of the first 3 areas in all patients (Z1, Z2, and Z3) and the visualization of the last area (Z4) in 19 patients (95%). On the other hand, the 30° scope allowed the detection of Z1 in 85% of patients, Z2 in 60% of patients, and Z3 in only 5% of patients. The medial portion of the trochlea was never visualized with the 30° scope. These findings were statistically significant.

Conclusions

The 70° scope improves visualization of the medial elbow compartment during elbow arthroscopy compared to the 30° scope, enhancing the extent of joint visualization and potentially permitting the detection of otherwise missed injuries in the difficult-to-reach areas of the joint.

Level of Evidence

Level II, diagnostic, prospective, cohort study.

Rehabilitation following ulnar collateral ligament injury of the elbow in a female acrobatic athlete: A case report

BACKGROUND

The mechanism of injury and the conservative rehabilitation of the ulnar collateral ligament of the elbow (UCL) are well studied and reported in overhead athletes, while research on gymnastic athletes is sparse. Evidence suggests exercise as the mainstay in UCL injury rehabilitation. With this report, we aimed to provide a complete rehabilitation protocol following a partial UCL tear of an acrobatic athlete, where exercise and adjunct treatments, such as manual therapy, were used in a progressive staged rehabilitation.

CASE DESCRIPTION

A 16-year-old female acrobatic athlete was diagnosed with partial tear of the anterior band of UCL. The rehabilitation included progressive exercise loading in conjunction with manual therapy for 10 sessions in 8 weeks. Pain, UCL special tests, the Disabilities of Arm, Shoulder and Hand Score Questionnaire (DASH), and the Upper Limb Functional Index (ULFI) were assessed and administered at baseline and at 3, 6, 10 weeks, and 3 months.

RESULTS

Improvement in all outcome measures was noted at the 3-month follow-up indicating a substantial reduction in pain and disability, and an increase in stability of the elbow joint. Return to training was achieved at 8 weeks from the initial visit, while return to sport at the pre-injury level was achieved at 3 months.

CONCLUSION

Progressive exercise loading along with the addition of manual therapy is an effective intervention for the rehabilitation and return to sport following a partial UCL tear. A progressive staged rehabilitation guideline for acrobatic athletes with UCL injuries has been provided to be used and guide clinical practice.

LEVEL OF EVIDENCE

Level IV.

A systematic review of techniques for step cut osteotomy in cubitus varus: A comprehensive analysis

Background

Cubitus varus, a common post-traumatic deformity of the elbow in children, poses challenges for both patients and surgeons. Step cut osteotomy has emerged as a reasonable surgical technique to address this condition, offering multiple approaches and modifications.

Methods

We present a comprehensive systematic review of techniques for step cut osteotomy in cubitus varus, analyzing 13 studies that meet our inclusion criteria. These studies encompass diverse patient populations, including pediatric and adult cases, and span different geographical regions.

Results

Our systematic review explores three primary osteotomy techniques-Classic Step-Cut Osteotomy, Reverse V Osteotomy, and Modified Step Cut Osteotomy-along with their modifications, providing surgeons with valuable options for individualized correction. Functional outcomes showcase improvements in range of motion, functional scores, and carrying angle, highlighting the technique's efficacy in restoring elbow function and enhancing quality of life. Radiological evaluations demonstrate successful corrections of various angles and achievement of bony union, reinforcing the stability and anatomical improvements achieved through step cut osteotomy.

Conclusions

Complication rates are notably low, with transient nerve palsies being the most commonly encountered, often resolving within months. Implant failure and other complications are infrequent, underlining the safety and reliability of step cut osteotomy as a surgical intervention for cubitus varus.While the predominance of retrospective studies and heterogeneity across included studies warrant caution, our systematic review provides a robust and diverse synthesis of evidence. It underscores the significance of step cut osteotomy in managing cubitus varus deformity, emphasizing its versatility, favourable outcomes, and safety profile. Further research with rigorous designs and longer follow-up periods will enhance our understanding of step cut osteotomy's role in cubitus varus correction.

A Dynamic Elbow Testing Apparatus for Simulating Elbow Joint Motion in Varying Shoulder Positions

Purpose

To develop and evaluate the capabilities of a dynamic elbow testing apparatus that simulates unconstrained elbow motion throughout the range of humerothoracic (HTA) abduction.

Methods

Elbow flexion was generated by six computer-controlled electromechanical actuators that simulated muscle action, while six degree-of-freedom joint motion was measured using an optical tracking device. Repeatability of joint kinematics was assessed at four HTA angles (0°, 45°, 90°, 135°) and with two muscle force combinations (A1-biceps brachialis, brachioradialis and A2-biceps, brachioradialis). Repeatability was determined by comparing kinematics at every 10° of flexion over five flexion-extension cycles (0° to 100°).

Results

Multiple muscle force combinations can be used at each HTA angle to generate elbow flexion. Trials showed that the testing apparatus produced highly repeatable joint motion at each HTA angle and with varying muscle force combinations. The intraclass correlation coefficient was greater than 0.95 for all conditions.

Conclusions

Repeatable smooth cadaveric elbow motion was created that mimicked the in vivo situation.

Clinical relevance

These results suggest that the dynamic elbow testing apparatus can be used to characterize elbow biomechanics in cadaver upper extremities.

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.

Impact of radiocapitellar interposition arthroplasty on ulnohumeral joint biomechanics

BACKGROUND

Radial head excision (RHE) has been shown to increase contact pressures within the ulnohumeral joint. Radiocapitellar interposition arthroplasty (RCIA) with the use of a soft tissue graft is an alternative for the treatment of isolated radiocapitellar arthritis or with failure of radial head replacement. We investigated contact pressures and contact area within the ulnohumeral joint after RHE compared to RCIA with dermal autograft.

METHODS

Six fresh-frozen cadaver elbows were tested on a custom dynamic elbow frame. A pressure sensor was inserted into the intact elbow joint, and mean contact pressure, peak contact pressure, contact area, and force within the ulnohumeral joint were recorded at 0°, 30°, 60°, 90°, and 120° of flexion as a valgus load was applied to the elbow. The radial head was then excised and specimens were retested. Finally, a dermal graft matched to the size of the resected radial head was inserted in the radiocapitellar space and the specimens were tested a third time.

RESULTS

At 90° of flexion, contact pressure within the ulnohumeral joint was significantly lower with RCIA compared with RHE (110.8 kPa vs 216.8 kPa; P = .013). The mean peak contact pressure was also significantly lower with RCIA compared with RHE at 90° (279.4 vs 626.7 kPa; P = .025). No statistically significant differences were seen in mean contact area or force between the 3 testing conditions at any flexion position.

CONCLUSION

RCIA with a dermal graft reduced contact pressures within the ulnohumeral joint compared to RHE at 90° of flexion without a significant change in contact area or contact force.

Coronoid fixation and lateral collateral ligament repair in varus posteromedial rotatory instability of the elbow

Background

Varus posteromedial rotatory instability is a relatively rare elbow injury, that has been infrequently reported in published literature. We intended to evaluate the outcomes of surgical management of this rare injury with anteromedial coronoid fixation, and, in selected patients, lateral ulnar collateral ligament (LUCL) repair.

Methods

Between 2017 and 2020, we identified 12 patients with anteromedial coronoid fractures, and a varus posteromedial rotatory instability, who underwent surgery for fixation of the coronoid fracture, with or without LCL repair. All the included patients were either O'Driscoll subtype 2-2, or subtype 2-3. All the 12 patients were followed up for a minimum of 24 months, and their functional outcomes assessed using the Mayo Elbow Performance Score (MEPS).

Results

The mean MEPS recorded in our study was 92.08, and the mean range of elbow flexion achieved was 124.2°. The mean flexion contracture in our patients was 5.83°. Three of our twelve patients (25%) suffered from elbow stiffness even at final follow-up. The results were graded as Excellent in eight, Good in three, and Fair in one patient.

Conclusion

Coronoid fractures and LUCL disruptions associated with varus posteromedial rotatory instability can be reliably managed by employing a protocol that combines radiographic parameters, as well as intra-operative assessments of stability. While surgical intervention successfully restored stability, there is a learning curve to the management of these injuries and complications are not uncommon, particularly elbow stiffness. Hence, in addition to surgical fixation, emphasis should also be placed on intensive post-operative rehabilitation to improve outcomes.

Immunofluorescence analysis of sensory nerve endings in the periarticular tissue of the human elbow joint

INTRODUCTION

To investigate the dynamic aspects of elbow stability, we aimed to analyze sensory nerve endings in the ligaments and the capsule of elbow joints.

MATERIALS AND METHODS

The capsule with its anterior (AJC) and posterior (PJC) parts, the radial collateral ligament (RCL), the annular ligament (AL), and the ulnar collateral ligament with its posterior (PUCL), transverse (TUCL) and anterior parts (AUCL) were dissected from eleven human cadaver elbow joints. Sensory nerve endings were analyzed in two levels per specimen as total cell amount/ cm² after immunofluorescence staining with low-affinity neurotrophin receptor p75, protein gene product 9.5, S-100 protein and 4',6-Diamidin-2-phenylindol, Carbonic anhydrase II and choline acetyltransferase on an Apotome microscope according to Freeman and Wyke's classification.

RESULTS

Free nerve endings were the predominant mechanoreceptor in all seven structures followed by Ruffini, unclassifiable, Golgi-like, and Pacini corpuscles (p ≤ 0.00001, respectively). Free nerve endings were observed significant more often in the AJC than in the RCL (p < 0.00002). A higher density of Ruffini endings than Golgi-like endings was observed in the PJC (p = 0.004). The RCL contained significant more Ruffini endings than Pacini corpuscles (p = 0.004). Carbonic anhydrase II was significantly more frequently positively immunoreactive than choline acetyltransferase in all sensory nerve endings (p < 0.05). Sensory nerve endings were significant more often epifascicular distributed in all structures (p < 0.006, respectively) except for the AJC, which had a pronounced equal distribution (p < 0.00005).

CONCLUSION

The high density of free nerve endings in the joint capsule indicates that it has pronounced nociceptive functions. Joint position sense is mainly detected by the RCL, AUCL, PUCL, and the PJC. Proprioceptive control of the elbow joint is mainly monitored by the joint capsule and the UCL, respectively. However, the extreme range of motion is primarily controlled by the RCL mediated by Golgi-like endings.

Reconstruction of the coronoid process with the olecranon tip for chronic elbow dislocation in children: A rare case report and literature review

The coronoid process of the ulna, as a key part of the elbow joint, plays an important role in maintaining elbow joint stability. Reconstruction of the coronoid process is necessary in both acute and chronic coronoid defects to restore elbow stability and avoid early joint degeneration. The olecranon tip may be a useful autologous osteochondral graft for reconstructing the same shape of the ulna coronoid process. The purpose of this report was to verify if reconstruction of the coronoid process with the olecranon tip can restore elbow stability and kinematics. Here, we report a 13-year-old boy who had undergone Kirschner-wire fixation for a left supracondylar fracture of the left humerus 9 years previously. After that, the right elbow dislocation and varus deformity gradually appeared. Imaging revealed posterolateral dislocation of the left elbow due to the absence of the coronoid process of the ulna. We reconstructed the ulnar coronoid process by intercepting the ipsilateral olecranon tip. After 22 months of follow-up, the range of motion of the left elbow joint was normal, and the cubitus varus deformity disappeared. The results of this report suggest that olecranon tip autografts are suitable to replace transverse coronoid defects. Given the patient's satisfactory clinical results, this reconstruction technique is safe and effective for the treatment of chronic elbow instability due to coronoid process defects of the ulna.

Repair Versus Non-Repair of Lateral Ulnar Collateral Ligament in Elbow Varus Posteromedial Rotatory Instability Treatment: A Comparative Study

OBJECTIVE

To compare the effects of repairing and not repairing the lateral ulnar collateral ligament (LUCL) when surgically treating elbow varus posteromedial rotatory instability (PMRI).

METHODS

In this retrospective study spanning June 2014 to February 2019, 24 patients with elbow PMRI who were treated surgically were assigned to group RL (Repair LUCL) or group NL (Non-repair LUCL) depending on whether the LUCL was repaired. Hospitalization time, operation time, intraoperative blood loss, and related complications were reviewed. The elbow range of motion (ROM), the visual analog scale (VAS), the Mayo elbow performance score (MEPS), and the disabilities of the arm, shoulder, and hand (DASH) score were used for functional assessment.

RESULTS

Among the 24 patients with PMRI, 15 were assigned to group RL and nine were assigned to group NL. The mean blood loss (184.66 ± 20.3 vs 207.33 ± 19.447, P < 0.001), the operation time (98.88 ± 12.693 min vs 184.66 ± 20.3 min, P < 0.001) were significantly lower in group RL compared to group NL. There were no significant differences between the two groups in time until surgery and follow-up time (6.66 ± 1.838 vs 6.11 ± 1.900 days, 25.53 ± 2.099 vs 26.11 ± 2.891 months, P = 0.577, P = 0.486). All of the patients achieved bone union. The elbow flexion-extension ROM (122.00° ± 3.162°vs 121.11° ± 3.333° at 12 months, P = 0.520) and pronation-supination ROM (154.53° ± 3.335° vs 155.55° ± 4.639° at 12 months, P = 0.537). Both groups achieved similar results in MEPS score (90.53 ± 2.695 vs 89.77 ± 3.865, P = 0.578) and DASH (9.77 ± 1.897 vs 9.99 ± 1.550, P = 0.772) score at the final follow-up. And the MEPS score revealed excellent results (87% in group RL, 89% in group NL).The VAS scores decreased significantly in group RL (from 6.13 ± 0.990 to 1.93 ± 0.593) and group NL (from 5.77 ± 1.481 to 1.88 ± 0.781), and no significant differences in preoperative or final follow-up were observed between the two groups (P = 0.487, P = 0.876). Complications observed in group NL with one patient occurred cubital tunnel syndrome 3 months after the operation, the patient underwent ulnar nerve simple neurolysis and the symptoms were relieved after 3 weeks.

CONCLUSION

For patients with elbow PMRI, satisfactory functional outcomes can be yielded with non-repair of the LUCL as long as the stable elbow joint is performed during operation.