Intrasynovial autograft for reconstruction of chronic large rotator cuff tears in a rabbit model: biomechanical, computed tomography, and histological results

BACKGROUND

Rotator cuff (RC) tears are a common cause of shoulder dysfunction and pain, posing significant challenges for orthopedic surgeons. Grafts have been proposed as a solution to augment or bridge torn tendons, but optimal clinical outcomes are not always achieved due to poor graft integration, suboptimal mechanical properties, and immunological reactions. The aim of this study was to investigate the biomechanical, CT and histological results of RC reconstruction using an intrasynovial tendon autograft, in a chronic large tear subscapularis rabbit model.

METHODS

Twenty-six adult male Zealand white rabbits were used in this study. Large defects in the subscapularis tendons were produced bilaterally in 20 rabbits. After 6 weeks, secondary procedures were performed to the right shoulder of the rabbits, which were reconstructed with an intrasynovial interposition autograft (graft group). The left shoulder did not undergo any further treatment (defect group). The specimens were randomly divided into two equal time groups and underwent biomechanical testing, CT analysis, and histological evaluation at 6, and 12 weeks after reconstruction. In addition, 6 rabbits that were not operated, were used as a control group.

RESULTS

At 12 weeks post-repair, the graft group exhibited a significant increase in ultimate failure load compared to the defect group (p < 0.05). Furthermore, the 12-week graft group demonstrated comparable stiffness to that of the control group. CT analysis indicated no significant progression of intramuscular fat accumulation in both graft groups, in contrast to the 12-week defect group when compared to the control group. Finally, histological evaluation revealed a gradual integration of the graft with the host tissue at 12 weeks.

CONCLUSION

Our study suggests that intrasynovial flexor tendon autografts hold promise as an effective interposition graft for the reconstruction of chronic large RC tears, as they improve the biomechanical and biological properties of the repaired tendon. Nonetheless, further investigations in preclinical large animal models are warranted to validate and extrapolate these findings to human studies.

Coverage of Palmar Mini Plates with Flexor Pulleys in the Treatment of Dorsal Fracture-Subluxation of the Proximal Interphalangeal Joint

Introduction: Dorsal fracture dislocations (DFD) of the proximal interphalangeal joint (PIPJ) are challenging fractures. A palmar surgical approach and plate fixation has a high complication rate, including flexor contractions, reduction of range of motion (ROM) and secondary need for plate removal. Methods: We use the flexor tendon pulleys to cover the mini plate with the assumption that it may reduce the adhesion between the mini plates and the tendons and reduce postoperative complications. We present the outcomes of using this technique in eight patients. Results: All patients had an excellent outcome at a mean follow-up of 17 months, and none required removal of the implants. Conclusions: This study presents a surgical technique that may potentially reduce the high complication rate found after ORIF for treatment of DFD of the PIPJ. Therefore, improving the clinical outcomes after this type of surgery. Level of Evidence: Level IV (Therapeutic).

An isolated rupture of the flexor digitorum tendon of the index finger following volar locking plate fixation of a distal radius fracture: A case report

Volar locking plates (VLP) have been widely used recently to treat distal radius fractures and are considered the gold standard. One of the most common complications of distal radius fracture surgery is flexor pollicis longus rupture, which may also occur in other tendons. Here, we report a case of isolated rupture of the flexor digitorum profundus to the index finger after VLP fixation of a distal radial fracture. Only a few cases of this have been reported in the literature. In previously reported cases, the cause of tendon rupture was repetitive mechanical stress due to implant protrusion. In our case, the plate was placed too distally; however, soft tissue completely covered the distal part of the plate. There was obvious synovitis within the carpal tunnel; therefore, pressure within the carpal tunnel may have increased. The cause of rupture in our case was thought to be a combination of direct mechanical stress and poor circulation due to inadequate VLP fixation.

Finger injuries by eyebrow razor blades in infants

Infants are occasionally injured while playing with their mother's eyebrow razor, and we have treated several infants with flexor tendon injuries, which in some cases were accompanied by damage to the corresponding digital nerves and/or vessels. Here, we report the outcomes in a retrospective case series, with a review of literature. Between January 2013 and October 2019, 8 patients who met our inclusion criteria were initially investigated. The inclusion criteria were: (1) injured by an eyebrow razor during fiddling or grasping, and (2) the availability of complete medical records and radiological data, with follow-up of at least 2 years. The core sutures were performed using a modified Becker (4-strand) method for flexor digitorum profundus (FDP). Nerves and/or vessels were repaired under microscopy. A long-arm mitten cast was then applied, with the fingers slightly flexed in a resting position, for 3 weeks. Then, the children were allowed to return to unrestricted activity. Formal outpatient hand therapy was not performed. Mean postnatal age was 6.3 months. The FDP was injured in zones 1 and 2 in 3 and 5 infants, respectively. Most of the infants were injured near a dressing table, in the bedroom used by their mother. The colors of these razors were all bright, except for one achromatic (white) razor. All of the razors had been left uncovered, without their cap, or were left open in the case of hinged razors. At a mean follow-up of 35.8 months, range of motion was evaluated by the Strickland and modified Strickland methods; all results were "excellent". We encountered no significant complications in any digit: neuroma, tendon retear, stiffness or necrosis. Uncapped or unfolded colorful eyebrow razors pose a high risk of tendon section with concurrent neurovascular injury in infants. Although satisfactory outcomes can be expected, it seems important to prevent the injury through fastidious parental care and changing razor design and color. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Closed Traumatic Zone 2 Flexor Tendon Injury of the Long Finger - A Case Report

Closed rupture of the flexor digitorum profundus (FDP) tendon causes loss of flexion at the distal interphalangeal joint. Following trauma, these are known to present as avulsion fractures (Jersey finger) commonly in ring fingers. Traumatic tendon ruptures at the other flexor zones are seldom noted and are often missed. In this report, we present a rare case of closed traumatic tendon rupture of the long finger FDP at zone 2. Though it was missed initially, was confirmed with Magnetic Resonance Imaging and underwent successful reconstruction using an ipsilateral palmaris longus graft. Level of Evidence: Level V (Therapeutic).

A Comparison of Outcomes at Twelve Weeks of Traditional Button-Over-Nail versus Bone Anchor Repair of Zone I Flexor Digitorum Profundus Tendon Injury

Background: The repair of zone 1 flexor tendon injury often relies on re-inserting the flexor digitorum profundus (FDP) tendon to the distal phalanx. The aim of this retrospective study is to compare outcomes at 12 weeks following traditional button-over-nail (BON) versus bone anchor (BA) repair of zone I FDP injury. Methods: Patients undergoing zone 1 FDP repair between April 2007 and September 2018 using a BON or a BA were included in the study. Patient demographics, complications, arc of flexion of distal (distal interphalangeal joint [DIPJ]) and proximal interphalangeal joint (PIPJ) and patient-rated outcomes were analysed. Results: Forty-three patients were included in the study: 21 in the BA group and 22 in the BON group. Good function was achieved by 20 patients in BA versus nine in BON. Complications occurred in five BA patients versus 10 BON patients. Patients achieved a mean active DIPJ flexion of 49° and 31° and PIPJ flexion of 92° and 57° in the BA and BON groups, respectively. Conclusion: Our study demonstrates better arc of motion, patient-rated outcomes and lower complications at 12 weeks after surgery in patients undergoing zone 1 FDP repair using a BA. Level of Evidence: Level III (Therapeutic).

The muscular branching patterns of the ulnar nerve in fetal forearms

OBJECTIVE

We aimed to present our findings systematically by examining the muscular branching patterns of the ulnar nerve (UN) in the forearms of fetuses.

METHODS

This study was conducted on the 52 forearms of 26 formalin-fixed fetal cadavers with gestational ages varying between 19 and 37 weeks. The anatomical dissection was performed by using stereomicroscope with × 8 magnification. The numbers of muscular branches leaving UN and their order of leaving main nerve were noted down. The findings were classified according to the muscles they reached, and branching typing was done.

RESULTS

It was found that a total of 2-6 muscular branches left UN to reach flexor carpi ulnaris (FCU) and flexor digitorum profundus (FDP). UN was classified by separating into five main types according to the number of muscular branches, and these types were classified into 16 different branching patterns according to the order of branches leaving from the main trunk and going to FCU and FDP. The pattern where two branches left UN was classified as Type I (n = 6), three branches left was classified as Type II (n = 18), four branches left was classified as Type III (n = 24), five branches left was classified as Type IV (n = 3), and six branches left was classified as Type V (n = 1). Martin-Gruber connection occurred in 17 (32.7%) fetal forearms.

CONCLUSION

We believe that the information that UN can demonstrate different branching patterns on the forearm can help the surgeons to prevent complications that may develop in potential nerve injury during the selection and transfer of relevant branch.

Tensile load on the flexor digitorum profundus tendon during palmar and lateral blocking exercises: Influence on blocking force and distal interphalangeal joint flexion angle

STUDY DESIGN

This is a basic science research.

INTRODUCTION

Isolating excursion of the flexor digitorum profundus (FDP) in zones I and II is common practice in the current management after flexor tendon repair. During this procedure, the proximal interphalangeal joint is sometimes fully extended with unmeasured external forces at the middle phalanx when the distal interphalangeal joint is actively flexed.

PURPOSE OF THE STUDY

The purpose of the study was to investigate the incremental effect of external force with palmar blocking versus lateral blocking and increased angles of flexion on internal tendon forces at the repair site for a safer application of force by the treating therapist.

METHODS

Eight human cadaveric fingers were studied. To simulate palmar or lateral finger blocking, a compression force of blocking was applied from 5N (510 grams) to 25N (2,550 grams) on the skin surface of the palmar or the lateral aspect of each of these middle phalanges in 5N increments. The tensile load on the FDP tendon during distal interphalangeal joint flexion from 0° to 60° was measured in 10° increments.

RESULTS

During palmar blocking, the tensile load was significantly increased with increases in palmar blocking force. However, no significant increase in the tensile load on the FDP tendon was observed at any lateral blocking.

DISCUSSION

Lateral blocking exercise can be performed with less tensile force on the FDP tendon when performing blocking exercise after flexor tendon injury repair.

CONCLUSIONS

This study supports the concept that lateral blocking with incremental joint angles allows a safer application of force for the healing tendon.

Anatomy and histomorphology of the flexor digitorum profundus enthesis: functional implications for tissue engineering and surgery

Background

The enthesis possesses morphological adaptations across the soft-hard tissue junction which are not fully restored during surgical avulsion repairs. This loss of anatomical structure, highly related to function, contributes to poor clinical outcomes. Investigating the native macro- and micro-structure of a specific enthesis can provide functional and biomechanical insights to develop specialised, novel tissue-engineered therapeutic options and potentially improve current surgical treatments for avulsion injuries.

Methods

This study examines the anatomy and histomorphology of the flexor digitorum profundus (FDP) enthesis in 96 fresh-frozen human cadaveric fingers, quantitatively and qualitatively analyzing the shape, size, angle of tendon fibres and histological architecture, and explores differences in sex, finger and distance along the enthesis using linear mixed effects models.

Results

Macroscopically, results showed a consistent trapezoidal insertion shape of 29.29 ± 2.35 mm² mean surface area, but with significant morphometric size differences influenced primarily by the smaller dimensions of the little finger. Microscopically, a fibrocartilaginous enthesis was apparent with a 30.05 ± 0.72^o mean angle of inserting tendon fibres, although regional variation in fibrocartilage and the angle change of tendon fibres before insertion existed.

Conclusions

The implication of these findings on native and specific FDP enthesis function is discussed whilst providing recommendations for optimal FDP enthesis recreation for interfacial tissue engineers and hand surgeons. The study emphasizes the importance of region-specific knowledge whilst also describing methods applicable to assessing any soft tissue insertion.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04922-1.

A reverse form of Linburg-Comstock variation with comments on its etiology and demonstration of interactive 3D portable document format

Purpose

Two most common variations of flexor pollicis longus include its accessory head and its connection with the flexor digitorum profundus of the index (Linburg–Comstock variation). In addition, while three-dimensional (3D) screening has widely been used in anatomical education, its use as reporting tool in anatomical research is still limited. The objective of this study is to report a previously unrecognized form of the accessory head of flexor pollicis longus, discuss the potential etiology of Linburg–Comstock variation, and pilot the 3D scanning of a large-scale anatomical structure.

Methods

An unusual tendon slip was discovered during a routine dissection in the anterior compartment of the right forearm of a 54-year-old male cadaver. A 3D scanner was used to capture the surface topography of the specimen and an interactive portable document format (PDF) was created.

Results

An anomalous tendon was found originating from the lateral aspect of the flexor digitorum profundus muscle. This variant tendon then inserted onto the medial surface of the flexor pollicis longus tendon before entering the carpal tunnel. The variation resembles a reverse form of Linburg–Comstock variation, because pulling this variant tendon resulted in simultaneous flexion of the interphalangeal joint of thumb.

Conclusion

Surgeons should be aware of the reverse Linburg–Comstock variation, because it may not be detectable by the conventional provocative testing. Linburg–Comstock variation may be classified as an anatomical variant or a secondarily acquired condition depending on its type. Our demonstration of interactive 3D-PDF file highlights its potential use for delivering anatomical information in future cadaveric studies.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00276-021-02858-8.

"Anterior interosseous nerve syndrome (Kiloh Nevin Syndrome) revealing Gantzer muscle and simultaneous myasthenia gravis"

There hasn't been a previous case report of the anterior interosseous nerve injury secondary to the presence of the muscle of Gantzer in a patient with myasthenia gravis in literature before. The anterior interosseous nerve compressive syndrome, also known as Kiloh-Nevin syndrome, is a rare disorder comprising less than 1% of all upper limb neuropathies. Establishing the etiology of anterior interosseous nerve compressive syndrome is challenging because of the lack of specific clinical findings or testing. Herein is the case of a 46 years-old male presented with left eye ptosis, ophthalmoparesis, diplopia, and right-hand weakness. On physical examination, the Pinch Grip test was positive. Electromyography studies showed neurogenic atrophy in the muscles innervated by the anterior interosseous nerve, as well as a pathological decrement of the muscle action potential of more than 10% on repetitive nerve stimulation. Concluding that the presence of the Gantzer muscle caused anterior interosseous nerve compressive syndrome was mainly a diagnosis of exclusion, after careful consideration of other possible etiologies including carpal tunnel syndrome, cervical radiculopathy, and Parsonage-Turner Syndrome. Even though anterior interosseous nerve compressive syndrome is very rare, clinical suspicion ought to arise in the presence of weak radial flexor digitorum profundus and flexor pollicis longus muscles. This case highlights the importance of a thorough medical history, a meticulous physical examination, and particularly the significance of electromyography studies in diagnosing different neuropathological entities. When appropriate, these steps offer information crucial to the differential diagnosis and eventual surgical management, assisting physicians in making informed and accurate treatment decisions.

The accessory heads of the muscles flexor pollicis longus and flexor digitorum profundus (Gantzer muscle) - An anatomical study in Brazilian cadavers

An important accessory anatomical variation, exclusively human, and related to the muscular ventres of the flexor pollicis longus and flexor digitorum profundus is frequently denominated Gantzer. These variations have close relations with the anterior interosseous nerve (AIN), which provides, for many authors, by direct compression, one of the rare neuropathic syndromes. In this work, thirty-four forearms were dissected from the collections of the Medical School of the Federal University of Minas Gerais and the Department of Basic Sciences of the Federal University of Juiz de Fora, with a prevalence of 50% of the 34 forearms studied for the Gantzer muscle. The muscle relationship was mainly with the flexor pollicis longus muscle and only one occurrence related to the flexor digitorum profundus muscle, described as a rare occurrence of unilateral double formation of Gantzer muscle. Bilaterality was observed in 88.23% of the findings and the dominant innervation for this muscle variation occurred in 82.35% by the anterior interosseous nerve (AIN). The type morphological in all forms found was the fusiform, with 10.5cm of total length and an average of 0.3cm in diameter and all related, as origin, in the medial aspect of the coronoid process of the ulna, next to the origin of the flexor digitorum superficialis muscle. Our work largely reflected the findings of most publications and, considering the controversy of the occurrence of a compressive neuropathy, the data were not sufficient, from a strictly anatomical point of view, to confirm or refute the hypothesis.

The sole rupture of flexor digitorum tendons to the index finger following volar locking plate fixation of distal radius fracture: A case report

Distal radius fracture is a common injury, especially in elderly people, and internal fixation with volar locking plate (VLP) is becoming an increasingly popular technique for the management of displaced and/or unstable distal radius fractures. One of the most common complications of this treatment is the flexor tendon rupture, mostly of the flexor pollicis longus (FPL). While the rupture of flexor digitorum tendons to the index (FDI) mostly occurs concomitantly with the rupture of FPL after the treatment using volar plating for distal radial fracture, sole rupture of the FDI without FPL rupture is very rare. Here, we report a case of the sole rupture of FDI after volar locking plating and analyze its pathogenesis indicating that the lift-up of the distal ulnar edge of the plate related to the malcorrection of the fracture site is the culprit for this specific complication.

Absence of flexor digitorum profundus muscle and variation of flexor digitorum superficialis muscle in a little finger: two case reports

PURPOSE

Knowledge of rare variants of the FDP is of high clinical importance for physicians examining patients for tendon lacerations and especially for hand surgeons operating tendon injuries.

METHODS

During routine dissection at our Department of Anatomy both cases were observed.

RESULTS

Variations of flexor digitorum superficialis and flexor digitorum profundus muscles of the little finger were observed in two cadavers. In both cases, the flexor digitorum profundus muscle for the little finger was absent. Moreover, in the first case, the flexor digitorum superficialis muscle for the little finger was hypoplastic and in the second case it featured variable insertion.

CONCLUSION

There were found only four cases in previous literature describing absent flexor digitorum profundus tendon without any muscle attachment to the base of the distal phalanx. Furthermore, all previously described cases were observed in living patients. To our best knowledge, a case report in cadaver has yet not been reported and is of high importance for hand surgeons examining the hand for tendon injuries.

An unusual Pattern of Flexor Digitorum Profundus Avulsion Injury with a Large Extra-articular Bony Fragment

Introduction:

Avulsion injury of the flexor digitorum profundus (FDP) tendon, commonly known as jersey finger, is seen in contact sports players such as rugby and football. There are mainly three patterns of this type of injury as mentioned in the Leddy and Packer classification on the basis of the level of retraction of the tendon. Subsequently, a Type IV injury was added by Smith, where the tendon was also separated from the avulsed bony fragment. It is the level of tendon retraction and the status of the long and the short vincula post-injury that determines the outcome of repair in these types of injuries.

Case Report:

Here, we report an unusual case of jersey finger injury in a 45-year-old male patient, where the FDP tendon was found in front of the middle phalanx with a large, fractured fragment of the middle third of the distal phalanx attached to it. This type of injury pattern has not been acknowledged in the commonly used classification systems. The patient was operated with open reduction and K-wire fixation of the bony fragment with a good functional outcome.

Conclusion:

While treating the cases of jersey finger injuries in sports players and general population, one should be aware of such rare patterns which can then be easily managed with proper pre-operative planning.

Prevalence of the Linburg-Comstock variation through clinical evaluation

INTRODUCTION

Linburg-Comstock variation, the tendinous interconnection between flexor pollicis longus and flexor digitorum profundus, is known to have a wide frequency range. Its prevalence is reported with a range of 13-66%. The aim of the study was to assess this variation in general population and to correlate it with gender and side.

MATERIAL AND METHODS

This prospective study included 215 subjects (82 males and 133 females). Two clinical tests were conducted to diagnose the variation and to detect any related symptomatology. The primary outcome was set to be the prevalence of Linburg-Comstock variation. Secondary outcomes were defined as gender-based prevalence, side-based prevalence, and Linburg-Comstock variation prevalence association with gender and side.

RESULTS

Linburg-Comstock variation was clinically diagnosed in 130 (60.47%) participants. Unilateral and bilateral prevalence were of 17.21% and 43.26%, respectively, yielding a statistically significant difference. Right-sided and left-sided presence were calculated at 7.44% and 9.77%. Bilateral prevalence was statistically more common in females. Right-sided variation was found to be more frequent in males while left-sided variation was more prevalent in females. The index finger was the most commonly involved with prevalence of 91.03%. Symmetry was noted in 67.74% of subjects.

CONCLUSION

The results of our study demonstrated a relatively high prevalence of the Linburg-Comstock variation in Serbian population. We noted a few unusual cases and this finding point to the existence of the broader spectrum of Linburg-Comstock variation, and complexity of the flexor apparatus of the hand, so, further investigations about this topic are needed to improve our knowledge. Due to the possibility of false-positive result during clinical testing we suggest to use expanded clinical method.

A comparison of fine wire insertion techniques for deep finger flexor muscle electromyography

INTRODUCTION

Intramuscular electromyography electrodes targeting flexor digitorum profundus (FDP) are inserted via the anterior or medial aspect of the forearm. These two methods pose different risks to neurovascular structures which overly FDP. This study aimed to compare the insertion depth and consider advantages and limitations of two different techniques to insert intramuscular electrodes into FDP.

METHODS

Using ultrasound imaging, neurovascular structures were identified along the path of FDP electrode insertion at the junction of the proximal and middle third of the ulna, bilaterally, in ten healthy individuals. Insertion depth was compared between the anterior and medial approaches for the mid muscle belly and targeted insertion to the index finger fascicle of FDP.

RESULTS

In our sample the ulnar artery was superficial to the FDP muscle when viewed anteriorly and was beyond the furthest border of FDP when viewed medially. Compared to the anterior approach, the medial insertion depth was 1.5 cm (95%CI 1.4-1.7, p < 0.001) less to the mid-belly of FDP and 0.6 cm (95%CI 0.4-0.7, p < 0.001) less to the index finger fascicle of FDP.

DISCUSSION

The medial approach involves less depth and lower risk for perforation of neurovascular structures when inserting intramuscular electrodes into the FDP muscle.

Linburg-Comstock variation: histoanatomy and classification of the connection between flexor pollicis longus and flexor digitorum profundus to the index finger

PURPOSE

The aim of the study was to investigate the anatomy and histology of Linburg-Comstock variation, or the anomalous connection between flexor pollicis longus and flexor digitorum profundus to the index finger, in Thai population.

METHODS

One hundred and thirty cadaveric upper limbs were dissected. Skin and superficial fascia on the anterior distal forearm and hand were removed. The tendons of the flexor pollicis longus and flexor digitorum profundus to the index finger were identified for the possible occurrence of the intertendinous connection. For histological analysis, selected specimens were sampled, and were stained with hematoxylin and eosin.

RESULTS

Out of 130 dissected upper limbs, interconnection between the two tendons was found in 32 limbs (25%). The connection was classified into three types including fibrous, tendinous, and musculotendinous. In 29 cases (22%), the connection was simply the thickening of synovial sheath between the two tendons. In two cases (1%) the connection was found as an additional tendinous slip of dense regular collagen bundles running from the flexor pollicis longus to flexor digitorum profundus of the index. In one case (1%), there was an aberrant reversed musculotendinous unit running from flexor pollicis longus, and later joined the first lumbrical.

CONCLUSIONS

This study provides a detailed anatomo-histological description of the interconnection between flexor pollicis longus and flexor digitorum profundus to the index finger. Its etiology could either be congenital or secondarily acquired. Surgeons should be aware of this connection for better diagnosis, surgical planning and treatment of diseased hands.

A New Classification Scheme for Closed Avulsion Injuries of the Flexor Digitorum Profundus Tendon

BACKGROUND

Closed avulsion injury of the flexor digitorum profundus (FDP) tendon is a relatively common condition of the hand. Its present classification system seems to be deficient in including all possible patterns of injury, leading to improper selection of the best treatment method for the injury. We aim to provide a new classification scheme for this injury.

METHODS

We developed a new classification scheme based on the possible pattern of FDP tendon injury. It consisted of three main types, and 10 sub-types. This was used to classify the injury of 34 patients, and help in choosing the best management approach. All patients underwent surgical treatment of their injury. The distal interphalangeal (DIP) joint extension deficit and total active motion (TAM) of the proximal interphalangeal (PIP) and DIP joints were considered as the main outcomes. Five orthopaedic surgeons used the new classification system for our cases, and the inter-rater reproducibility was tested with Fleiss' kappa.

RESULTS

The multi-rater kappa for the classification was excellent. At the final follow-up visit 24 months following surgery, the mean loss of extension of the DIP joint was 13.76° ± 13.53° (range 0° to 45°), while the mean TAM was 148.88° ± 22.64° (range 94° to 172°). Based on the TAM score, 21 (61.76%), 8 (23.53%) and 5 (14.71%) patients had excellent, good and fair results, respectively. None of our patients had poor results.

CONCLUSIONS

Our new classification scheme of FDP tendon avulsion appeared to be comprehensive and useful in guiding the surgeon for the best treatment option. Nevertheless, this should be confirmed by using it for larger number of patients with different patterns of injury.

MRI in flexor tendon rupture after collagenase injection

Flexor tendon rupture is an unusual complication following collagenase injection to relieve contractures. These patients require a close follow-up and in the event of tendon rupture, a decision has to be made whether to repair the tendon or manage the complication conservatively. The authors report the utility of MRI in the prognostication and management of a patient with Dupuytren's contracture, who underwent collagenase injection and subsequently developed flexor digitorum profundus tendon rupture.

Variant lumbrical musculature of the left hand: Clinico-anatomic elucidation

Human hand is haughtily described in literature as 'revolution in evolution'. Lumbricals form an intricate part of its musculature playing a vital role in complex digital movements. By virtue of their origin from the volar aspect of palm and their insertion onto the dorsal aspect to the extensor digital expansion of the digits, lumbricals display complex actions flexing the metacarpophalangeal joint and extending the interphalangeal joints. Such manoeuvres of the digits are vital for skilful and precision movements. During routine dissection of the teaching program of undergraduate medical students, unusual origin and morphology of all the four lumbrical muscles in the left hand of a male cadaver was observed. Clinicians and hand surgeons should be aware of its variations while designing and dealing with hand surgeries. An attempt has been made to comprehend its clinical, embryological and phylogenetic aspects.

Spontaneous flexor tendon rupture secondary to capitate non-union. A case report and review of literature

Rupture of the flexor digitorum profundus and superficialis tendons of the index finger secondary to non-union of the capitate has not yet been reported to our knowledge. We describe the case of a 48-year-old man with rupture of both flexor tendons of the index finger that occurred 15 years after a capitate fracture. The patient was completely asymptomatic before the rupture. Tendon reconstruction was performed using the palmaris longus. One year after surgery, the patient had acceptable range of motion and was pain-free.

Attritional Rupture of the Little Finger Flexor Digitorum Profundus Tendon in the Carpal Tunnel in a Patient with Acromegaly

Spontaneous rupture of flexor tendons within the carpal tunnel is rare in the absence of rheumatoid arthritis. Other predisposing conditions such as gout, infection, pisotriquetrial osteoarthritis, as well as hook of hamate fracture non-union, have previously been reported. However, tendon ruptures of the hand in the presence of acromegaly, as well as spontaneous ruptures within the carpal tunnel, have not been described in the literature.

Validity of parameters in static linear testing of flexor tendon repair

To study the biomechanical properties of flexor tendon repairs, static tensile testing is commonly used because of its simplicity. However, cyclic testing resembles the physiological loading more closely. The aim of the present study is to assess how the biomechanical competence of repaired flexor tendons under cyclic testing relates to specific parameters derived from static tensile testing. Twenty repaired porcine flexor tendons were subjected to static tensile testing. Additional 35 specimens were tested cyclically with randomly assigned peak load for each specimen. Calculated risks of repair failure during repetitive loading were determined for mean of each statically derived parameter serving as a peak load. Furthermore, we developed a novel objective method to determine the critical load, which is a parameter predicting the survival of the repair in cyclic testing. The mean of statically derived yield load equalled the mean of critical load, justifying its role as a valid surrogate for critical load. However, regarding mean of any determined parameter as a clinically safe threshold is arbitrary due to the natural variation among samples. Until the universal performance of yield load is verified, we recommend employing cyclically derived critical load as primary parameter when comparing different methods of flexor tendon repair.

Avulsion Injuries of the Flexor Digitorum Profundus Tendon: An Unclassified Pattern of Injury

Closed avulsion of the flexor digitorum profundus (FDP) tendon is classified based on the impact of injury on the management plan. In this report, we present a case with unclassified pattern of FDP tendon avulsion. The injury involves an intra-articular fracture of the volar part of distal phalanx of the little finger resulting into two bony fragments, one attached to the retracted avulsed tendon and another separated and incarcerated at A4 pulley, and an intact dorsal cortex of the phalanx. Based on that, we recommend the development of a new classification scheme for this condition.

The outcomes of zone 1 flexor tendon injuries treated using micro bone suture anchors

This article evaluates the outcome of 42 consecutive zone 1 flexor tendon injuries treated by using micro bone anchors during the period 2003-2008. Patients were rehabilitated using the modified Belfast Regime. The range of motion at the distal interphalangeal joint was assessed using Moiemen's classification. A total of 56% of patients achieved excellent or good results for range of motion at the distal interphalangeal joint and 23% had a poor outcome. The mean distal interphalangeal joint and proximal interphalangeal joint range of motion were 48° and 96°, respectively. A total of 94% of patients returned back to work by 12 weeks. One patient sustained a tendon rupture and one developed osteomyelitis. The mean QuickDASH score was 13.5 and 81% of patients were satisfied with their outcomes. This is the largest clinical study on the use of bone anchors for zone 1 tendon injuries. Our study demonstrated a low rate of complications and outcomes that compare favourably with other published techniques.

Conservative treatment in Jersey finger: a case report

We report a case of a Type Vb flexor digitorum profundus tendon avulsion in a patient for whom surgery was contraindicated because of a high risk of stroke if anticoagulant treatment was to be stopped. After a 6-week conservative treatment and a 3-week self-physiotherapy programme, the patient achieved a nearly full active range of motion and an excellent functional result. A radiograph demonstrated a good fracture healing.

LEVEL OF EVIDENCE

V.

Multiple musculovascular anomalies in the superior extremities of a cadaver: a case report

During the evolution from the lower animals to man, the upper limbs have acquired a great mobility, but at the cost of their stability. The reverse is true for the lower limbs. The muscular anomalies which are common in the upper limbs are largely explainable on a phylogenetic basis. The same is true for the vascular anomalies. However, such anomalies are usually seen singly and they are never together in the same limb or in two limbs of the same body. The upper limbs which are being reported here had multiple musculovascular anomalies and some of these were bilateral. These include the superficial brachial artery, the accessory head of the biceps brachii, the accessory muscular slips which arose from the common flexor origin and went to the tendons of the flexor digitorum profundus and the flexor pollicis longus separately, bifurcation of the tendon of insertion of the brachioradialis and bifurcated (split) insertion of the third lumbrical on the adjacent fingers. Though all these variations have been described in the standard text books of Anatomy, their occurrence, together in one limb and the bilateral presentations of some of these, have never been encountered. Almost all these variations have been explained phylogenically, thus supporting the dictum, "The ontogeny repeats the phylogeny." Furthermore, their clinical significance has also been discussed.

Nerve transfer strategies for spinal cord injury

BACKGROUND

Spinal cord injury (SCI) is a devastating condition, which beleaguers its victims with long-term health issues. Nerve transfer is a feasible option for restoration of critical limb function in patients with SCI that potentially improves independence and quality of life.

METHODS

This article delineates the general principles of nerve transfer and its specific application pertinent to SCI. The available nerve transfer strategies are described based on the targeted limb function, mostly involving critical upper extremity function. The role of nerve transfer for paraplegia, diaphragm reanimation, and bladder reinnervation is also discussed.

RESULTS

Nerve transfer offers several advantages over the traditionally used tendon transfer.

CONCLUSIONS

Nerve transfer does not require prolonged immobilization and provides greater functional gain for a given transfer. Reconstruction of several facets of upper limb function potentially can be performed in a single stage. The merits of nerve transfer deserve further study to evaluate its value for spinal cord injury in humans.

A rare presentation of flexor digitorum profundus type V avulsion injury with associated intra-articular fracture: A case report

Traumatic avulsions of the flexor digitorum profundus tendon are associated with young adults engaged in athletic activities such as football and rugby. The current report presents a case involving a 30-year-old man with traumatic avulsion of his flexor digitorum profundus and associated intra-articular distal phalangeal fracture secondary to injury during martial arts - an unusual cause of this injury. Increased attention to injuries acquired during this form of sporting activity is suggested.