Biomechanical characterization of cadaveric brachial plexus microstructure.

INTRODUCTION: Peripheral nerves consist of axons and connective tissue. The amount of connective tissue in peripheral nerves such as the brachial plexus varies proximally to distally. The proximal regions of the brachial plexus are more susceptible to stretch injuries than the distal regions. A description of the mechanical behavior of the peripheral nerve components is necessary to better understand the deformation mechanisms during stretch injuries. The purpose of this study was to model the biomechanical behavior of each component of the peripheral nerves (fascicles, connective tissue) in a cadaveric model and report differences in elastic modulus, maximum stress and maximum strain. METHODS: Forty-six specimens of fascicles and epi-perineurium were subjected to cyclical uniaxial tensile tests to obtain the stress and strain histories of each specimen, using a BOSE® Electroforce® 3330 and INSTRON® 5969 materials testing machines. Maximum stress, maximum strain and elastic modulus were extracted from the load-displacement and stress-strain curves, and analyzed using Mann-Whitney tests. RESULTS: Mean elastic modulus was 6.34 MPa for fascicles, and 32.1 MPa for connective tissue. The differences in elastic modulus and maximum stress between fascicles and connective tissue were statistically significant (p < 0.001). CONCLUSIONS: Peripheral nerve connective tissue showed significantly higher elastic modulus and maximum stress than fascicles. These data confirm the greater fragility of axons compared to connective tissue, suggesting that the greater susceptibility to stretch injury in proximal regions of the brachial plexus might be related to the smaller amount of connective tissue.

Biomechanical characterization of cadaveric brachial plexus regions using uniaxial tensile tests.

INTRODUCTION: The proximal regions of the brachial plexus (roots, trunks) are more susceptible to permanent damage due to stretch injuries than the distal regions (cords, terminal branches). A better description of brachial plexus mechanical behavior is necessary to better understand deformation mechanisms in stretch injury. The purpose of this study was to model the biomechanical behavior of each portion of the brachial plexus (roots, trunks, cords, peripheral nerves) in a cadaveric model and report differences in elastic modulus, maximum stress and maximum strain. METHODS: Eight cadaveric plexi, divided into 47 segments according to regions of interest, underwent cyclical uniaxial tensile tests, using a BOSE® Electroforce® 3330 and INSTRON® 5969 material testing machines, to obtain the stress and strain histories of each specimen. Maximum stress, maximum strain and elastic modulus were extracted from the load-displacement and stress-strain curves. Statistical analyses used 1-way ANOVA with post-hoc Tukey HSD (Honestly Significant Difference) and Mann-Whitney tests. RESULTS: Mean elastic modulus was 8.65 MPa for roots, 8.82 MPa for trunks, 22.44 MPa for cords, and 26.43 MPa for peripheral nerves. Differences in elastic modulus and in maximum stress were statistically significant (p < 0.001) between proximal (roots, trunks) and distal (cords, peripheral nerves) specimens. CONCLUSIONS: Proximal structures demonstrated significantly smaller elastic modulus and maximum stress than distal structures. These data confirm the greater fragility of proximal regions of the brachial plexus.

Long-term outcome of fibula flaps in complex limb reconstruction compared to alternative procedures, a median follow up of 41 months.

INTRODUCTION: Complex open long bone fractures present a multidisciplinary surgical challenge. Various treatment options are discussed with no consensus. Fibula flaps (FF) are frequently used in maxillofacial surgery, however their use in limb injuries is less common. With the tremendous improvement in microsurgery, orthoplastic surgery gained importance. Our retrospective study aims to assess the long-term results and the quality of life of the patients operated by FF for complex traumatic limb reconstruction. PATIENTS AND METHODS: We conducted an observational mono centric retrospective study from the year 2011 to the year 2021. Patients operated for complicated traumatic limb fractures using FF were included in the study. Not only long-term clinical results were evaluated, but also Patient-reported outcome measures (PROM). These included the Lower Extremity Functional Scale (LEFS), Quick Disabilities of the Arm, shoulder and hand (Qdash), and the Visual Analogue Scale (VAS). The statistical analysis was done using the R Software. RESULTS: Twenty patients were included in our study. 80% achieved complete union with no re fracture rate at a median follow-up of 41 months. All of the patients (n = 4) who underwent amputation were smokers (p = .09), were operated for lower limb fractures (p = .54), and were males (p = 1). The length of hospital stay was associated with an increased duration to complete bony union (p = .01, coefficient = 2.88). At the end of follow-up, the LEFS median score was 67 for the total population and 63.5 for the lower limb reconstructed sub group. CONCLUSION: VFF is an important tool in the armamentarium of orthoplastic surgeons. Encouraging long term functional and clinical outcomes were obtained in patients with complex traumatic limb fractures.

Outcomes of Arthrodesis of the Metacarpophalangeal Joint of the Thumb for Sequelae of Collateral Ligament Injuries: A Series of 18 Cases with 6-Year Follow-Up.

Background: Untreated or insufficiently treated collateral ligament injuries of the thumb metacarpophalangeal (MP) joint can lead to instability or even osteoarthritis. Arthrodesis is one of the treatment options available for the treatment of the sequelae of collateral ligament injuries. The objective of our study was to evaluate the radiological, clinical and functional outcomes of MP joint arthrodesis performed for sequelae of collateral ligament injuries. Methods: We conducted a retrospective, single-centre study and reviewed the files of patients who had a thumb MP joint arthrodesis following a collateral ligament injury between 2011 and 2019. We collected patient's demographic data and the results of the radiological and clinical examinations. Results: Eighteen patients were included in the study. The average age was of 53.6 years and the time between injury to arthrodesis averaged 7 years. Four patients (22%) had nonunion. In the remaining 14 patients with solid union at an average of 72 months follow-up, the visual analogue pain score at rest was 0.14, the thumb opposition was 82%, grip strength 85%, tip pinch 92% and key pinch 79% of the contralateral side. Conclusions: The clinical and functional results of patients with a successful arthrodesis are satisfactory with restoration of good grip and pinch strength. Despite a lack of thumb MP joint flexion, stability allowed force transmission and may be preferred for manual workers. Level of Evidence: Level IV (Therapeutic).

Cadaveric study of flexor digitorum profundus and superficialis and flexor pollicis longus innervation patterns for application in selective neurectomy.

PURPOSE: Spasticity management in finger flexors (flexor digitorum profundus and superficialis and flexor pollicis longus) is a challenge. Recent studies demonstrated the short- and long-term efficacy of selective and hyperselective neurectomy for the spastic upper limb. However, hyperselective neurectomy of flexor digitorum profundus and flexor digitorum superficialis branches was incomplete, without impairing their muscular body and function. This cadaveric study describes a novel medial approach in the forearm, to reach all the muscular branches: flexor digitorum superficialis and profundus and flexor pollicis longus. MATERIAL AND METHODS: Fourteen cadaveric fresh frozen upper limbs were used. The feasibility of the medial surgical approach was studied, as well as the number, length and point of emergence of the muscular branches from the median and ulnar nerves to the flexor pollicis longus, flexor digitorum profundus and flexor digitorum superficialis. RESULTS: The medial approach to the forearm gave access to all the muscular branches from the median and ulnar nerves to the flexor pollicis longus, flexor digitorum superficialis and flexor digitorum profundus, in all cases. A Martin Gruber communicating branch was found in 7 cases out of 14. CONCLUSION: The medial approach to the forearm gave access to all the muscular branches from the median and ulnar nerve to the flexor pollicis longus, flexor digitorum superficialis and flexor digitorum profundus, without extensive transmuscular dissection of the pronator teres or flexor digitorum superficialis muscles. This approach opens the way for selective neurectomy of the flexor pollicis longus, flexor digitorum profundus and flexor digitorum superficialis muscles. LEVEL OF EVIDENCE: IV.

Ligamentoplasty in scapholunate instability: short-term results of the "all dorsal scapholunate repair" technique.

Injury to the scapholunate complex is the cause of scapholunate instability which can lead to radiocarpal and medio-carpal osteoarthritis. Several ligamentoplasty techniques have been reported for the treatment of chronic scapholunate instability before the osteoarthritis stage. The objective of this study was to assess the short-term results of an "all dorsal scapholunate repair" ligamentoplasty. We report the clinical, radiological and functional results of a retrospective study including 21 patients, operated between June 2019 and December 2020 for a stage 3 or 4 scapholunate instability according to the Garcia Elias classification. With a follow-up of 14.2 months, the pain was 0.1/10 according to the VAS at rest and 4/10 during exercise. Wrist strength was measured at 65% of the opposite side. The flexion-extension range of motion was 105°. Radiologically, there was a reduction of the diastasis and scapholunate angle. Osteolysis areas around the anchors were described in 47% of patients. The mean QuickDASH was 29.2/100, PRWE 24/100 and Mayo wrist score 67.8/100. Eighty-one percent of patients were satisfied. Seventeen patients had returned to work 5.2 months postoperatively. In the case of work-related injury, the functional scores were poorer, with a delayed return to work. This technique provides encouraging results in the short term. Most patients were improved compared to preoperative state. The work-related injury appears to be a poor prognostic factor. A longer-term study is imperative to confirm the maintenance over time of the correction of carpal malalignment and the evolution of the osteolysis areas.Level of evidence: Level IV Retrospective study.

Comparison of proximal row carpectomy with RCPI® versus proximal row carpectomy with Eaton's capsular interposition in the management of advanced wrist osteoarthritis.

INTRODUCTION: Proximal row carpectomy (PRC) is one of the recommended techniques for managing wrist osteoarthritis, it implies the integrity of the lunate fossa of the radius and the proximal pole of the capitate. If PRC is not possible, it is suggested to consider combining it with a capsule interposition (such as Eaton's flap) or opting for intra- or radiocarpal arthrodesis. Another alternative is to combine capitate resurfacing with a pyrocarbon implant (RCPi®). The aims of this study was to assessed the results between proximal PRC+Eaton and those associated PRC+RCPi® for advanced wrist osteoarthritis. HYPOTHESIS: We hypothesized that there would be no differences in clinical or functional outcome between proximal row carpectomy associated with RCPI® and those associated with Eaton capsular flap. MATERIAL AND METHODS: It is a monocentric, retrospective, multi-operator study involving 83 wrists with osteoarthritis, included between January 2000 and December 2020 with a minimum follow-up period of 12 months. Thirty-nine patients underwent PRC+Eaton and 44 patients underwent RCPI® resurfacing. Data such as pain, flexion, extension and strength as well as functional scores (PRWE, Mayo and quick DASH) were collected from the patient files at the last check-up. RESULTS: Results were comparable between the two groups in terms pain (VAS), mobility (flexion and extension), strength (GRASP) and functional scores (PRWE, Mayo and quick DASH). Carpal height was better preserved in the PRC+RCPI® group, with a Youm and McMurtry index evaluated at 0.3 in the PRC+Eaton group compared to 0.4 in the PRC+RCPI® group (p-value<0.001). Radiocarpal arthrodesis was required in 16% of the PRC+Eaton group and 6.8% of the PRC+RCPI® group, with a statistically significant difference (p-value=0.023). DISCUSSION: This study reports clinical and functional results that suggest RCPI® is an interesting alternative and can be associated with proximal row carpectomy in advanced wrist osteoarthritis. LEVEL OF EVIDENCE: IV; retrospective study.

Radial nerve lesion after medial epicondyle osteosynthesis in a pediatric patient: A rare complication of surgery.

Fractures of the medial epicondyle are relatively common in children and may be associated with nerve lesion, especially in case of displacement. Incarceration of the ulnar nerve in the fracture site is feared in Watson-Jones stage II, rarely directly related to osteosynthesis. Depending on the degree of fracture displacement, various osteosynthesis techniques may be used; nerve injuries are a rare but known complication of these procedures. We report a case of radial nerve injury related to pinning osteosynthesis of a medial epicondyle fracture.

Recent and chronic sprains of the First Metacarpo-Phalangeal Joint.

Sprains of the first metacarpo-phalangeal joint (MCPJ) are a common form of hand injury that mainly affects the ulnar collateral ligament. Although the diagnosis is made on the physical findings, radiographs must be obtained and ultrasonography or magnetic resonance imaging (MRI) is necessary in some cases. If the joint is unstable or a bony fragment is displaced, surgery must be performed within 4 weeks after the injury. Beyond this interval, ligament reconstruction is the preferred treatment. The objective of this article is to provide evidence, from both older and recent studies, that guides the choice of the best treatment in clinical practice. To this end, we will address the following questions: (1) What is a Stener lesion? (history and pathophysiology); (2) In addition to the physical examination, what other investigations are appropriate in doubtful cases? (with special attention to the indications of ultrasonography and MRI); (3) What are the clinical and radiological criteria for performing surgery in patients with acute first MCPJ sprains? (4) What reconstruction procedures are appropriate in patients with acute or chronic MCPJ sprains?

Lower-limb Flip-Flap: A simple reliable modification of adipofascial flap for extensive tibial crest cutaneous defect.

INTRODUCTION: Large cutaneous defects exposing the whole tibial crest are difficult to cover and are conventionally best treated with free flaps. This article describes a technical modification of the adipofascial flap in this indication. METHODS: The "flip-flap" is vascularized by the posterior tibial artery perforators harvested on the medial aspect of the leg. The hypodermal and fascial tissue is de-epidermized and elevated from the posterior midline up to the medial edge of the soleus muscle, then folded over the exposed tibial crest like a page of a book. RESULTS: A 27×6cm effect was successfully covered on a 72 year-old patient with vascular status precluding free flap. The flap healed by day 21. DISCUSSION/CONCLUSION: This technical modification is simple and allows coverage of large tibial crest skin defect when a free flap is not possible.

Non-healing ischaemic digital ulcer in a systemic sclerosis patient: a challenging clinical case.

Ischaemic digital ulcers (DUs) are an indicator of the severity of the microangiopathy in patients with systemic sclerosis (SSc). DUs are a frequent complication, affecting about 50% of patients with SSc, and are often recurrent. In cross-sectional studies involving patients with SSc, the frequency of ischaemic DUs was 12-16% with a major impact on hand function and quality of life. Effective therapy for DUs remains elusive. Intravenous iloprost has been demonstrated to have a positive effect on healing of active DUs. Bosentan, an oral endothelin receptor antagonist, only showed a benefit in preventing the occurrence of new DUs. Despite limited evidence, recent guidelines have recommended phosphodiesterase type 5 inhibitors as an option. Injection of botulinum toxin and digital sympathectomy have been increasingly used for ischaemic DUs. Here we present the complex case of a SSc patient already treated with sildenafil and bosentan in whom an active DU was successfully treated with botulinum toxin A. Despite the lack of a randomised controlled trial, results are encouraging for the use of botulinum toxin in the treatment of DUs and could perhaps help to avoid some amputations, as in the present case.

Perilunate dislocations and transscaphoid perilunate fracture-dislocations: a retrospective study with minimum ten-year follow-up.

PURPOSE: Perilunate dislocations and transscaphoid perilunate fracture dislocations are associated with a high incidence of posttraumatic arthritis. According to the current literature, at medium-term follow-up, radiological signs of arthritis do not correlate with functional scores. The aim of this study was to evaluate patient hand function and the development of posttraumatic arthritis after perilunate dislocations (11 cases) and transscaphoid perilunate fracture dislocations (7 cases) at a minimum 10 years of follow-up. METHODS: A retrospective review was performed including 18 patients with a minimum 10-year (average, 13 y) follow-up. The clinical results were evaluated using the Mayo wrist score and the patient-rated wrist evaluation. Radiological abnormalities were stratified using the Herzberg classification. RESULTS: According to the Mayo wrist score, the authors found 5 excellent, 3 good, 7 fair, and 3 poor results. The mean Mayo wrist score was 76 (range, 60-90). There were 6 type A, 5 type A1, 6 type B1, and 1 type C, according to the Herzberg classification. Posttraumatic degenerative changes were observed in 12 cases. CONCLUSIONS: The presence of radiological arthritis and static carpal instability did not cause reduced function at our minimum follow-up of 10 years. Based on our findings and previously reported series, we conclude that signs of posttraumatic arthritis after perilunate dislocations and transscaphoid perilunate fracture dislocations increase progressively but are well tolerated at an average follow-up of 13 years. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Pulley rupture and reconstruction in rock climbers.

Hand-grip techniques in modern rock climbing generate climbing-related injuries, especially at the flexor tendon sheath level. The most frequent injury is A2 pulley rupture. The clinical diagnosis is based on bowstringing of the flexor tendon and confirmed by computed tomograph scan or magnetic resonance imaging. The surgical procedure is based on an extensor retinaculum graft to reconstruct the ruptured pulley. It is the only efficient treatment regardless of the time between accident and surgery. Thanks to this surgical procedure, patients recover or improve their former climbing performance. Some precautions before climbing may prevent this injury, and these are listed.