Case report illustrating use of serial elastic tension digital neoprene orthoses (ETDNO) protocol in the treatment of proximal interphalangeal joint flexion contracture.

INTRODUCTION: This case report details the application of a treatment regimen using a serial elastic tension digital neoprene orthosis (ETDNO) protocol for a patient with an eight-month-old finger crush injury who experienced recurrence of a 45º proximal interphalangeal joint (PIPJ) flexion contracture two months after arthrolysis. PURPOSE OF THE STUDY: To illustrate how the application strategy of ETDNO can increase the daily total end range time (TERT) and modify finger stiffness. RESULTS: The patient reached full extension following 15 weeks of ETDNO treatment. The six-month follow-up evaluation revealed that the PIPJ was stable with full flexion and extension. The joint did not require continued orthosis use. DISCUSSION: The literature describes orthosis application as the treatment of choice for PIPJ flexion contracture, but no study has described an ideal program for use nor the full and stable resolution of the flexion contracture. The current literature describes a maximum daily total end range time (TERT) of 12 hours a per day. The serial ETDNO protocol that this study described increased the daily TERT to nearly 24 hour per day and demonstrated an excellent result in the treatment of PIPJ flexion contracture CONCLUSION: This outcome suggests that clinicians will want to consider this new orthosis design and management protocol as a novel option for the treatment of PIPJ flexion contracture. We need future research to better define the optimum number of hours of daily TERT for the effective treatment of PIPJ flexion contracture. In addition, we will also benefit from the exploration of the optimum orthosis design to enable the highest amount of TERT.

Influence of forearm rotation on the kinetic stabilizing efficiency of the muscles that control the scapholunate joint. Clinical application in proprioceptive and neuromuscular rehabilitation programs.

BACKGROUND: This study focuses on the relationship between forearm muscles, carpal ligaments, and their impact on scapholunate joint stability across varying forearm rotations. This is crucial for optimizing pre and postoperative rehabilitation strategies for scapholunate joint dysfunction. PURPOSE: Our study aims to understand the kinetic influence of forearm muscles on scapholunate joint instability. We emphasize the significance of forearm rotation to enhance treatment efficacy. STUDY DESIGN: We conducted an experimental study to understand how forearm muscles contribute to the stability of the scapholunate joint during different degrees of forearm rotation and we focused on the joint effect of muscle groups rather than individual muscles for treatment protocols. RESULTS: Our findings shed light on the conservative treatment of dynamic scapholunate instability and the postoperative rehabilitation of scapholunate ligament repair. We found that the effect of forearm muscles significantly contributes to preserve stability in the scapholunate joint across various forearm rotational positions. These insights have practical implications for hand therapists, offering innovative strategies to enhance clinical practice. CONCLUSIONS: This research underscores the importance of considering forearm rotation when developing rehabilitation protocols for scapholunate joint instability and provides a valuable perspective in line with current rehabilitation principles.

Bicipital tuberosity bone characteristics in surgical reattachment of the distal biceps: anatomical and radiological study.

PURPOSE: The aim of this study was to measure the cortical thickness and bone density of the different parts of the bicipital tuberosity, to evaluate the importance of these variables on resistance to pulling out of distal biceps tendon reinsertion implants. METHODS: Sixteen cadaveric arms were used for this study. A multiple detector computed tomography was performed in each proximal radius. Bone thickness and density of anterior, posterior cortex and anterior trabecular bone were measured in proximal, medial and distal parts of the bicipital tuberosity. Statistical and concordance analyses of results were performed. RESULTS: In our specimens, the medial and distal parts of the anterior cortex and the anterior trabecular bone were thicker, mean 11.3 mm SD 2.72 and 11.17 mm SD 3.05, with a significant difference when compared to the proximal part; mean 10.3 mm SD 2.35, of radial tuberosity. The three posterior segments where all thicker compared to the anterior cortex (proximal 3.15 SD 1.31; medial 3.33 SD 1.5; distal 3.34 SD 1.43 mm), but without statistical differences between them. The measured bone density was equivalent in the three portions of the anterior cortex and trabecular bone [proximal 1924.63 SD 547.22; medial 1848.19 SD 538.59; distal 2100.47 SD 396.32 Hounsfield units (HU)]. The posterior cortex was denser compared to the anterior cortex and the anterior trabecular bone in all the segments (proximal 1962.63 SD 223.57; medial 1907.16 SD 232.08; distal 1987.06 SD 189.12 HU), but without statistical differences between the three parts. CONCLUSIONS: Based on the results of this anatomic study which have demonstrated that anterior cortex and anterior trabecular bone of the medial and distal regions of the bicipital tuberosity are thicker than proximal part, we postulate that these segments could give better pulling out resistance to monocortical implants. Our findings suggest that the strongest parts of the bicipital tuberosity are the proximal and medial parts of the posterior cortex. We can afford them drilling across the radius using a bicortical implant in the proximal and medial section of the radial tuberosity. Furthermore, we suggest that an increased margin of safety could be achieved to prevent injury to the posterior interosseous nerve, drilling the cortical hole in the proximal part of the radial tuberosity without losing resistance properties.

Role of muscles in the stabilization of ligament-deficient wrists.

This article reviews the results of a series of cadaver investigations aimed at clarifying the role of muscles in the stabilization of ligament-deficient wrists. According to these studies, isometric contraction of some forearm muscles induces midcarpal (MC) supination (ie, the abductor pollicis longus, extensor carpi radialis longus, and flexor carpi ulnaris), whereas other muscles induce MC pronation (ie, the extensor carpi ulnaris). Because MC supination implies tightening of the volar scaphoid-distal row ligaments, the MC supination muscles are likely to prevent scaphoid collapse of wrists with scapholunate ligament insufficiency. MC pronator muscles, by contrast, would be beneficial in stabilizing wrists with ulnar-sided ligament deficiencies owing to their ability to tighten the triquetrum-distal row ligaments. Should these laboratory findings be validated by additional clinical research, proprioceptive reeducation of selected muscles could become an important tool for the treatment of dynamic carpal instabilities.

Transverse coronoid fracture: when does it have to be fixed?

BACKGROUND: After elbow fracture-dislocation, surgeons confront numerous treatment options in pursuing a stable joint for early motion. The relative contributions of the radial head and coronoid, in combination, to elbow stability have not been defined fully. QUESTIONS/PURPOSES: The purpose of this study was to evaluate the effect of an approximately 50% transverse coronoid fracture and fixation in the setting of an intact or resected radial head on coronal (varus/valgus) and axial (internal and external rotational) laxity in (1) gravity varus stress; and (2) gravity valgus stress models. METHODS: Kinematic data were collected on six fresh-frozen cadaveric upper extremities tested with passive motion throughout the flexion arc under varus and valgus gravity stress with lateral collateral ligaments reconstructed. Testing included coronoid fracture and osteosynthesis with and without a radial head. RESULTS: In the varus gravity stress model, fixation of the coronoid improved varus stability (fixed: 1.6° [95% confidence interval, 1.0-2.2], fractured: 5.6° [4.2-7.0], p < 0.001) and internal rotational stability (fixed: 1.8° [0.9-2.7], fractured: 5.4° [4.0-6.8], p < 0.001), but radial head fixation did not contribute to varus stability (intact head: 2.7° [1.3-4.1], resected head: 3.8° [2.3-5.3], p = 0.4) or rotational stability (intact: 2.7° [0.9-4.5], resected head: 3.9° [1.5-6.3], p = 0.4). With valgus stress, coronoid fixation improved valgus stability (fixed: 2.1° [1.0-3.1], fractured: 3.8° [1.8-5.8], p < 0.04) and external rotation stability (fixed: 0.8° [0.1-1.5], fractured: 2.1° [0.9-3.4], p < 0.04), but the radial head played a more important role in providing valgus stability (intact: 1.4° [0.8-2.0], resected head: 7.1° [3.5-10.7], p < 0.001). CONCLUSIONS: Fixation of a 50% transverse coronoid fracture improves varus and internal rotatory laxity but is unlikely to meaningfully improve valgus or external rotation laxity. The radial head, on the other hand, is a stabilizer to resist valgus stress regardless of the status of the coronoid. CLINICAL RELEVANCE: Determination as to whether it is necessary to fix a coronoid fracture should be based on the stability of the elbow when tested with a varus load. The elbow may potentially be stable with fractures involving less than 50% of the coronoid. Under all circumstances, the radial head should be fixed or replaced to ensure valgus external rotatory stability.

Radial head reconstruction in elbow fracture-dislocation: monopolar or bipolar prosthesis?

BACKGROUND: Monopolar and bipolar radial head prosthetic arthroplasties have been used successfully to treat elbow fracture-dislocation with unsalvageable radial head fractures. The relative stability of these two designs in different clinical situations is a topic of ongoing investigation. QUESTIONS/PURPOSES: We tested the effects of monopolar and bipolar fixed-neck prosthetic radial head implants on improvement in elbow coronal and axial plane laxity in a terrible triad biomechanical model that accounted for lateral collateral ligament integrity and the presence of a transverse coronoid fracture. METHODS: Kinematic data were collected on six fresh-frozen cadaveric upper extremities tested with passive motion throughout the flexion arc. Varus and valgus gravity stress were applied with the wrist in neutral position. A lateral collateral ligament reconstruction was simulated. We assessed instability after radial head resection and reconstruction with either a monopolar or bipolar implant in the presence of a transversely fractured (Regan and Morrey Type 2) or fixed coronoid process. RESULTS: With collateral ligament integrity, no difference was detected, with the numbers available, in valgus laxity between implants under valgus stress (p = 1.0). Laxity improvement with each prosthesis was higher when the coronoid was fractured (mean ± SD: monopolar: 7.4° ± 1.6°, p < 0.001; bipolar: 6.4° ± 1.6°, p = 0.003) than when it was fixed (monopolar: 4.0° ± 1.6°, p = 0.02; bipolar: 4.2° ± 1.6°, p = 0.01). With the numbers available, there was no difference in external rotation laxity between implants under valgus stress (p = 1.0). The greatest stabilizing effect of the prostheses occurred when the coronoid was fractured (monopolar: 3.3° ± 1.2°, p = 0.15; bipolar: 3.3° ± 1.2°, p = 0.17). Radial head arthroplasty offered no substantial stability under varus stress for varus or internal rotation laxity. CONCLUSIONS: In our terrible triad cadaveric model, coronoid fixation was effective in improving varus laxity with a monopolar or bipolar prosthesis in place. Also, both types of prostheses were effective in improving valgus and external rotation laxity to the elbow, regardless of coronoid status. With collateral ligaments reconstructed, no large kinematic differences were noted between implants regardless of the varus-valgus position or whether the coronoid was fractured or fixed. CLINICAL RELEVANCE: The data from our cadaveric model support the use of either implant type in terrible triad injuries if the collateral ligaments are intact or reconstructed.

Role of the extensor carpi ulnaris in the stabilization of the lunotriquetral joint. An experimental study.

STUDY DESIGN: Experimental laboratory-based research in biomechanics. INTRODUCTION: The mechanisms by which some lunotriquetral (LTq) ligament disruptions remain stable are not known. PURPOSE OF THE STUDY: To investigate the contribution of muscles in preventing carpal destabilization when the LTq ligaments are torn. METHODS: Ten fresh cadaver wrists, set vertical in a jig, were isometrically loaded through five wrist motor tendons. Changes in carpal alignment secondary to the application of loads were monitored by a Fastrak™ electromagnetic motion tracking device, before and after sectioning the LTq ligaments. RESULTS: After LTq ligaments sectioning, wrist loading forced the triquetrum into flexion (5.4° average) and supination (2.9 ). The only muscle capable of extending and pronating the collapsed triquetrum was the extensor carpi ulnaris (ECU). CONCLUSIONS: Inadequate ECU muscle function is an important destabilizing factor in LTq deficient wrists. Dynamic LTq instabilities may benefit from proprioceptionally training the ECU muscle, while avoiding carpal supination torques.

Necrotizing fasciitis: Usefulness of the LRINEC score in a third-level hospital.

AIM: To review patients seen in the emergency room, diagnosed with necrotizing fasciitis (NF) and the correlation of such complications with the Laboratory Risk Indicator for Necrotizing fasciitis scale (LRINEC). The purpose of this study is to assess the use of the LRINEC score for early diagnosis of NF and its prognostic use in a consecutive series of cases treated at our hospital. METHODS: Retrospective observational study including patients with a diagnosis of NF in the emergency room of a tertiary hospital over 11 years. The results are shown as median, interquartile range and absolute range for quantitative variables. In the case of qualitative variables, the results are shown as absolute and relative frequency. The comparison between the categories of the LRINEC scale was performed through a post-hoc comparison from a non-parametric rank-ANOVA analysis. Comparisons between LRINEC groups in the qualitative variables were performed using Fisher's exact test. RESULTS: A total of 45 patients with a mean age of 51 years were identified. There was a 20% mortality rate (9 cases). The highest mortality rate was registered in the high-risk group (LRINEC greater than 8) with 4 deceased individuals (44.44%), while in the low and moderate-risk groups, 3 and 2 deceased individuals (33% and 22%) were registered, respectively, without considering this result statistically significant (p=0.811). There was an amputation rate of 15.6% (7 cases). The average LRINEC score was greater in the cases that required amputation 9 (95% CI 7; 13) in comparison to the other patients, 6 (95% CI 5; 8), p=0.044. The average hospital stay lasted 32.5 days (95% CI: 25; 40); 30 days in the low-risk group, 41 days in the moderate-risk group and 40 days in the high-risk group. Mortality was associated to a smaller number of interventions (p=0.005) and was preceded by septic shock in all cases. CONCLUSIONS: The LRINEC score may be useful to aid diagnosis. However, clinical suspicion is the most important in diagnosis. A LRINEC low score does not exclude NF. In this retrospective series, 35.71% of cases presented a low LRINEC score, making the rate of false negatives high. In view of these results, The LRINEC score cannot be used as a prognostic value since an initial low score does not rule out serious evolution.

Kinetic dysfunction of the wrist with chronic scapholunate dissociation. A cadaver study.

BACKGROUND: Most laboratory studies investigating scapholunate dissociations are based on normal cadaver arms with serially sectioned ligaments. It is assumed that the kinetic behavior of a ligament-sectioned wrist is similar to a scapholunate dissociation. We tested five cadaver wrists with real injuries. The goal of this research was to evaluate the biomechanical behavior of scapholunate advanced collapse wrists compared to an experimental group with simulated injuries. METHODS: Using a magnetic 6-degree of freedom motion tracking device, changes in scaphoid alignment induced by isometric loading 5 wrist motor tendons in two groups of specimens were monitored. Twelve fresh cadaver wrists in which scapholunate injury was simulated by sectioning the scapholunate ligament were compared to 5 arms with chronic scapholunate dissociation. FINDINGS: The behavior of the scaphoid is the same in both groups, but the magnitude of displacement is greater in chronic scapholunate dissociation wrists, although not statistically significant. The extensor carpi ulnaris is the only muscle that provokes scaphoid pronation; all other muscles induce its supination. INTERPRETATION: Different factors may play a role in the amount of scaphoid rotation observed in wrists with chronic scapholunate dissociation. Ligament sectioning alone in the experimental setup can only partially replicate the behavior of real scapholunate dissociations. The extensor carpi ulnaris has a major role in destabilizing scapholunate advanced collapse wrists; therefore, isometric contraction of this muscle should be avoided in the conservative treatment. The experimental setup designed is useful to evaluate the biomechanical behavior of the carpus under traction load.

The anterior limited approach of the elbow for the treatment of capitellum and trochlea fractures: Surgical technique and clinical experience in eight cases.

When a coronal fracture affects the capitellum and the trochlea, the Kocher lateral approach may be inadequate for the correct visualisation, reduction and fixation of the fracture. In such cases an associated medial elbow approach may be required, or a posterior transolecranon approach may be preferred. The anterior limited approach to the elbow (ALAE) could be a valid option when treating these types of fracture, as it does not involve the detachment of any muscle group or ligament, thereby facilitating the recovery process. We can also treat associated injuries such as fractures of the radial head or coronoid process with this approach. We describe the surgical technique and the functional outcome of eight patients with a mean of 66 years of age (range, 53-76) who where treated with open reduction and internal fixation for capitellar and trochlear fractures through the ALAE. Patient outcomes were assessed with physical and radiological evaluation, range-of-motion measurements with a follow-up from 24 to 60 months. Two different quality of life questionnaires were carried out: the EuroQol Five Dimensions Questionnaire (EQ-5D) and the patient-answered questionnnaire of the Liverpool Elbow Score patient (PAQ-LES). Four fractures involved the capitellum, one involved the capitellum with the lateral ridge of the trochlea, and three involved the capitellum and trochlea as separate fragments. The patients presented a favorable clinical evolution at a median of 33 months (range, 24-60), with an average of motion of 10-138°. Four patients presented a fracture of the head of the radius (Mason type 2) and 3 fractures of the coronoid (Bryan-Morrey Type 1) associated. All the patients presented radiological consolidation without signs of osteonecrosis, being the average EQ-5D 0.857 (range, 0.36-1.0) and the PAQ-LES of 35 (range 17 to 36). Patients with isolated capitellar fractures had better results than those with trochlear involvement. The presence of associated fractures does not seem to worsen the results. We believe that the ALAE is a technical option to consider for the open surgical treatment of a capitellar fracture with or without involvement of the trochlea. LEVEL OF EVIDENCEIS: Therapeutic Level III.

Tendon transfer fixation in the foot and ankle: a biomechanical study.

BACKGROUND: Tendon transfers are often used in foot and ankle surgery. Different fixation devices and techniques have been described. The most recently developed ones are bone anchors and interference screws. MATERIALS AND METHODS: A biomechanical study was designed to compare tendon transfer fixation, using Corkscrew bone anchors 5 x 15.5 mm and Bio-interference screws (8 x 23 mm). Fifteen fresh cadaver specimens underwent both fixation techniques for split anterior tibial tendon transfer at the cuboid bone. All the specimens underwent standardized X-rays in order to evaluate mineral bone density using a standardized measurement system. All were tested until maximal load to failure. RESULTS: The ultimate load to failure of the tendon secured to the cuboid using anchors was 103 N (SD, 52), compared with 150 N (SD, 68) for tendons secured to the bone with interference screws (p = 0.003). No difference was found between the techniques that could be related to bone density. CONCLUSION: Interference screws provided greater strength than bone anchors. CLINICAL RELEVANCE: This study demonstrated increased strength in securing bone to tendon in vitro for SPLATT tendon transfer with interference screws as compared to suture anchors.

A biomechanical comparison of the modified Bunnell pullout and Teo intraosseous suture techniques for attachment of tendon to bone.

We compared the biomechanical properties of the Teo intraosseous suture technique with the modified Bunnell pullout technique in a cadaver model after a tendon to bone repair. Thirty-six fresh-frozen cadaveric fingers were assigned randomly to three groups (Teo, Bunnell and control groups). They were loaded cyclically from 2 to 15 N at 25 mm/min, for 500 cycles. Gap formation at the repair site was assessed every 100 cycles and then specimens were tested to failure. The Teo group had an approximately 30% smaller gap every 100 cycles and needed 30% more energy to obtain a 2 mm gap than the modified Bunnell group. Displacement after 500 cyclic loads was significantly lower in the Teo group than in the Bunnell group. For the failure of the Teo suture, it was necessary to apply 31% more load than the Bunnell technique.

Trapeziometacarpal Ligaments Biomechanical Study: Implications in Arthroscopy.

Purpose In the presence of early osteoarthritis, changes to the trapeziometacarpal joint (TMJ) often result in pain and is associated with joint instability and a tendency of dorsoradial subluxation. In these instances, arthroscopy may be indicated to: (1) assess the extent of cartilage disease and the laxity of ligaments and to (2) treat TMJ instability. The purpose of our study was to biomechanically analyze which ligaments are the primary stabilizers of the TMJ. Methods Overall, 11 fresh-frozen human cadaver specimens were dissected and attached to a testing device with the thumb positioned in neutral abduction, neutral flexion, and neutral opposition. The four extrinsic and five intrinsic muscle tendons acting on the TMJ were simultaneously loaded with weights proportional to their physiological cross-sectional area. The dorsal, volar, and ulnar groups of ligaments were dissected. A motion-tracking device, FasTrak (Polhemus Inc., Colchester, VT), was used to study the spatial position of the base of the first metacarpal bone (MC1), before and after random sectioning of each of the ligaments. Statistical analysis of the MC1 translation along the transverse XY plane was performed using one-way analysis of variance and a paired t-test, with a significance level of p < 0.05. Results After isolated sectioning of the volar or the ulnar ligaments, the MC1 moved dorsoradially with an average of 0.150 mm (standard deviation [SD]: 0.072) and 0.064 mm (SD: 0.301), respectively. By contrast, the destabilization of the MC1 after sectioning of the dorsal ligaments was substantially larger (0.523 mm; SD: 0.0512; p = 0.004). Conclusion Sectioning of the dorsal ligament group resulted in the greatest dorsoradial translation of the MC1. Consequently, the dorsal ligaments may be regarded as the primary TMJ stabilizers. Clinical Relevance This study suggests that stabilizing arthroscopic shrinkage of the TMJ should be targeted toward the dorsal TMJ ligaments.

Relationship Between Wrist Motion and Capitolunate Reduction in Four-Corner Arthrodesis.

The authors retrospectively studied 36 patients with degenerative changes associated with scaphoid nonunion and scapholunate advanced collapse treated with circular plate fixation and bone graft. The goals of the study were to review the incidence of dorsal impingement, nonunion of arthrodesis, loose hardware, broken screws, and limitation in wrist motion associated with correct or incorrect surgical capitolunate reduction. Surgical indications were scapholunate advanced collapse (3 patients), scaphoid nonunion advanced collapse (32 patients), and sequelae of irreducible perilunate dislocation (1 patient). All of the patients were men, with a mean age of 48 years (range, 35-68 years). Average follow-up was 56 months (range, 12-108 months). Functional outcomes evaluated were pain with the visual analog scale, range of motion, grip strength, Disabilities of the Arm, Shoulder and Hand (DASH) score, satisfaction, and time to union. Mean visual analog scale score was 7 (range, 5-9) preoperatively and 1 (range, 0-2) postoperatively. Average wrist range of motion was 42° in extension, 36° in flexion, 15° in ulnar deviation, and 12° in radial deviation. Mean grip strength was 34 kg preoperatively, 50 kg postoperatively, and 56 kg contralaterally. Thirty-five of the 36 patients achieved union at 6 months. Degenerative changes at the radiolunate articulation were present in 1 patient 62 months after surgery, but he was asymptomatic. Mean capitolunate angle was 38º preoperatively and 9º postoperatively. Poor correlation was found between the measured capitate-lunate angle and subsequent flexion and extension (r=0.32 and r=0.17, respectively) using the Pearson correlation coefficient. The authors noted 1 or 2 broken screws in 3 cases (8.3%) and hardware dorsal impingement in the plate in 6 cases (16.6%). Mean DASH score was 24 of 100. Overall patient satisfaction was 70%.

How to Avoid Ulnar Nerve Injury When Setting the 6U Wrist Arthroscopy Portal.

The dorsal sensory branch of the ulnar nerve (DSBUN) is at risk in setting the 6U wrist arthroscopy portal. Although surgeons know the risk and are careful when they set the 6U portal, DSBUN injuries still occur. The purpose of the present anatomical study was to evaluate the possibility that DSBUN undergoes dynamic anatomical variations in its location during wrist arthroscopy. The goal of the study was to clarify (1) whether the nerve-to-portal (NTP) distance changes with flexion/extension wrist and/or hand/forearm rotation, and (2) whether there is any particular combination of flexion-extension/hand-forearm rotation where the NTP distance is maximal. Six fresh cadaver arms were suspended in a traction tower with forearm rotation locked, the skin and subcutaneous tissue around the ulnar head was removed, and the NTP distance measured in three predetermined loading/positional conditions. Of all options, the one that consistently showed the longest and safest NTP distance involved wrist flexion and radiocarpal supination when forearm rotation is limited. In conclusion, when an arthroscopic traction device restricts the forearm rotation, the 6U portal should not be set under traction with the hand passively pronated. Failure to observe this precaution can result in serious neuropathic pain.