Surmounting the Learning Curve of Core Suture Placement with Tendon Repair Simulator.

BACKGROUND: Attaining competency in placement of core suture with adequate distance from juncture is a key skill for learners of tendon repair. Currently, this is most commonly practiced on animal models in wet laboratory environment. To improve accessibility and availability, we developed a tendon repair trainer that aims to guide learners in obtaining this key competency. METHODS: A customized tendon dock was designed and manufactured with additive method that permits insertion of 6mm silicon tendon rods to simulate flexor tendon repair along a digit. Four residents, divided into two groups, were instructed to repair two sets of tendon rods (60 rods per resident) with Kessler suture loop placed at 10 mm from juncture (Group A: rods marked at 10 mm, Group B: unmarked rods). The main criterion for passing was a loop placed within 1 mm of the target distance (10 mm). At a second session, both groups repaired unmarked tendons, and these were marked based on similar criterion. RESULTS: At the first session, 100% of those who repaired marked rods (Group A) passed while 25% of unmarked rods (Group B) attained a pass. At the second session, where both groups repaired unmarked rods, residents from group A achieved a pass rate of 95% while group B achieved 33.3% pass. CONCLUSIONS: Learners who had previously repaired marked rods were able to retain their experience when repairing unmarked rods. This suggest that the proposed model may be a helpful adjunct to sharpen learners' skills prior to practicing tendon repairs in more costly animal or cadaveric models.

Peripheral Nerve Lymphomatosis.

Lymphoma involvement of peripheral nerves is rare and it may mimic benign neurogenic tumors or neuropraxic injury. This study presents three patterns of presentations in four patients with neurolymphomatous involvement of their peripheral nerves. We reviewed the clinical records of four patients who underwent exploratory brachial plexus surgery (n = 1), pronator tunnel decompression (n = 1) and peripheral nerve exploration (n = 2) and subsequently found to have neurolymphomatosis (NL). Histological diagnoses were diffuse large B-cell lymphoma (n = 3) and NK/T-cell lymphoma (n = 1). NL lacks pathognomonic clinical and imaging features that aid clinicians in diagnosis. Apart from a history of lymphoma, and high clinical index of suspicion, PET-CT scans appear to be a helpful adjunct in detecting high metabolic lesions occuring in situ or systemically. Intra-operative frozen section is helpful to detect round blue cells, before final cytological diagnosis.

Biomechanics of Internal Fixation Modalities for Middle Phalangeal Base Fracture Dislocation.

BACKGROUND: Internal fixation modalities of unstable (>50 percent articular involvement) middle phalangeal volar lip fracture-dislocations include interfragmentary screw and volar buttress plating. This study investigates the mechanical properties (yield strength, ultimate tensile strength, and stiffness) of interfragmentary screw (IS), simple buttress plating (BP) and buttress plating with subchondral screw (BP+S). METHODS: Fifteen cadaveric digits (5 index, 5 middle, and 5 ring) were prepared by excising its skin envelope and flexor tendons while preserving the structures around the proximal interphalangeal joint. An oblique osteotomy involving 50 percent of the articular surface was performed, and this was fixed with based on its study group: interfragmentary screw (IS), simple buttress plating (BP) and buttress plating with subchondral screw (BP+S). These specimens were then loaded to failure. RESULTS: Yield strength was as follows: BP+S (33.5±9.76 N), IS (13.6±5.46 N), and BP (8.1±3.84 N). Ultimate tensile strength was as follows: BP+S (49.1±21.4 N), IS (15.6±5.19 N), and BP (8.86±3.99 N). Stiffness was as follows: BP+S (4.77±1.32 N/mm), IS (2.44±0.86 N/mm), and BP (1.84±0.71 N/mm). CONCLUSIONS: A buttress plate and screw construct confers significantly more stability than either interfragmentary screw or buttress plate only fixation in an experimental model.

Post-Reduction Stability of the Proximal Interphalangeal Joint after Dorsal Fracture Dislocation-A Cadaveric Study.

BACKGROUND: Proximal interphalangeal joint (PIPJ) dorsal fracture dislocations (DFD) are challenging injuries. Treatment aims to achieve stability of the PIPJ after reduction so that early motion can be initiated. We studied how increasing articular destruction would affect post reduction stability and investigate the amount of traction and PIPJ flexion needed to maintain the reduction. METHODS: Increasing amounts (20%, 40% and 60%) of damage to the volar lip of the middle phalanx in cadaveric specimens were created to represent PIPJ DFD that were stable, of tenuous stability and frankly unstable. Traction forces and PIPJ flexion needed to maintain the reduction were then measured. RESULTS: The PIPJ DFD with 20% damage were stable and did not subluxe while the one with 40% articular involvement was stable after reduction. For unstable the PIPJ with 60% involvement, the more the PIPJ was flexed, the less traction force was needed to hold the joint in reduction. For PIPJ flexion of 20 degrees, a minimum 4.4N of force is needed to maintain reduction while PIPJ flexion of 10 degrees required a minimum 5.0N of force. No amount of force could maintain PIPJ reduction if traction was performed in full extension. CONCLUSIONS: In our model, PIPJ DFD with less than 30% articular damage are stable while those with 30% to 50% of involvement have tenuous stability. For the unstable PIPJ DFD, traction obviates the need for excessive flexion of the PIPJ to maintain joint reduction. This information should be considered in treatment modalities for PIPJ DFD, as well in the design of external traction devices for the treatment of PIPJ DFD.

Tips and Tricks in Mallet Fracture Fixation.

We describe three steps to aid fracture assessment and fixation in the extensor block pin technique for mallet fractures. The first step is the use of fluoroscopy in the initial assessment to determine indication for fixation. Next is the use of supplementary extension block pin to control larger dorsal fragments. The third technique described details the steps of open reduction of nascently malunited fractures.

Relation of Lateral Antebrachial Cutaneous Nerve to the Volar Approach to Distal Radius.

BACKGROUND: The anatomy of the lateral antebrachial cutaneous nerve (LABCN) in relation to volar approaches to the distal radius is not well visited. With the increasing popularity of distal radius fracture fixation with volar locking plates, it is prudent to study the innervation pattern of the LABCN to minimize the risk of nerve injury. METHODS: Ten cadaveric distal radial forearms were dissected to study the relationship between the LABCN, flexor carpi radialis (FCR), superficial branch of radial nerve (SBRN), and scaphoid tubercle (ST). RESULTS: The LABCN coursed closer to the FCR than the SBRN, with branches traversing the tendon in two specimens. The LABCN was also noted to be intimately related to the radial artery, with an average distance of the LABCN from the lateral border of FCR was 6.4mm distally and 9.6mm proximally. CONCLUSIONS: There is a sparsely innervated corridor between the radial border of the FCR and terminal branches of the LABCN that provides safe access for volar approach to the distal radius.

Intramuscular schwannoma: clinical and magnetic resonance imaging features.

INTRODUCTION: Schwannomas that arise within the muscle plane are called intramuscular schwannomas. The low incidence of these tumours and the lack of specific clinical features make preoperative diagnosis difficult. Herein, we report our experience with intramuscular schwannomas. We present details of the clinical presentation, radiological diagnosis and management of these tumours. METHODS: Between January 2011 and December 2013, 29 patients were diagnosed and treated for histologically proven schwannoma at the National University Hospital, Singapore. Among these 29 patients, eight (five male, three female) had intramuscular schwannomas. RESULTS: The mean age of the eight patients was 40 (range 27-57) years. The most common presenting feature was a palpable mass. The mean interval between surgical treatment and the onset of clinical symptoms was 17.1 (range 4-72) months. Six of the eight tumours (75.0%) were located in the lower limb, while 2 (25.0%) were located in the upper limb. None of the patients had any preoperative neurological deficits. Tinel's sign was present in one patient. Magnetic resonance (MR) imaging showed that the findings of split-fat sign, low signal margin and fascicular sign were present in all patients. The entry and exit sign was observed in 4 (50.0%) patients, a hyperintense rim was observed in 7 (87.5%) patients and the target sign was observed in 5 (62.5%) patients. All patients underwent microsurgical excision of the tumour and none developed any postoperative neurological deficits. CONCLUSION: Intramuscular schwannomas demonstrate the findings of split-fat sign, low signal margin and fascicular sign on MR imaging. These findings are useful for the radiological diagnosis of intramuscular schwannoma.

Proposed Guidelines for Treatment of Concomitant Distal Radius and Distal Ulna Fractures.

BACKGROUND: Concomitant distal radius and distal ulna metaphysis or head fractures (DRUF) are uncommon and acceptable results have been reported from cast immobilisation and internal fixation. METHODS: We reviewed the charts of 1094 patients treated for distal radius fracture at our institution in a two year period from 2009 to 2010. 24 patients with concomitant DRUF with were treated by cast immobilisation (group 1, n = 11), internal fixation of both bones (group 2, n = 7), internal fixation of radius alone (group 3, n = 2), and internal fixation of radius with distal ulna resection (group 4, n = 4). Patients treated by surgery underwent intraoperative assessment of distal ulna stability to determine the indication for ulna fixation. Post surgical range of motion, clinical parameters, and functional outcome scores (Gartland-Werley and modified Mayo) were measured. RESULTS: Wrist motion was comparable in each group. Radiographic parameters were better in surgical groups. 23 of 24 patients achieved excellent/good outcomes based on Gartland-Werley scores, while 12 of 24 achieved good modified Mayo wrist score. There was a case of distal ulna non-union in group 1, and another case of delayed distal radius union in group 2. CONCLUSIONS: By evaluating patients' functional requirement, and dynamic fluoroscopy examination, satisfactory outcomes can be achieved for various presentations of DRUF.

Well-camouflaged Skin Graft Donor Sites in the Hand.

Three full-thickness skin graft sites within the hand where the donor sites are well blended with surrounding skin contour and crease are described. Two of these donor sites are located within the digit and these provide nonglaborous skin for small defects of the hand, whereas the third donor site along the palmar crease provides glaborous skin. These donor sites provide ease of access, minimal morbidity, and well-matched skin for resurfacing of small defects around the hand. The indications, contraindications, and technical points of each donor site are discussed.

Crescent flap for fingertip reconstruction.

A volar advancement flap based on V-Y concept for fingertip reconstruction is described. The crescent flap utilises curved incision to preserve fingertip contour and distal digital crease. Satisfactory outcome was achieved in two patients who underwent fingertip reconstruction using this technique. Its advantages are technical simplicity, minimal donor morbidity, and may be used in situation where conventional V-Y incision is unsuitable.

Cross-finger dermal pocketing to augment venous outflow for distal fingertip replantation.

Venous anastomosis in distal fingertip replantations is not always possible, and venous congestion is recognized as a potential cause of failure. Methods previously described to address this problem include amputate deepithelization and dermal pocketing postarterial anastomosis to augment venous outflow. However, attachment of the digit to the palm or abdomen resulted in finger stiffness. We describe a modification of the previous methods by utilizing dermal flaps raised from the adjacent digit in the form of a cross-finger flap. The key differences are the partial deepithelization of the replanted fingertip and subsequent replacement of the dermal flap to the donor digit to minimize donor site morbidity. During the period where the 2 digits are attached, interphalangeal joint mobilization is permitted to maintain joint mobility.

Comparison between cast immobilization versus volar locking plate fixation of distal radius fractures in active elderly patients, the Asian perspective.

Displaced distal radius fractures in active elderly patients with high functional demand present a clinical dilemma because current evidence is equivocal in the recommendation of treatment. Internal fixation is an increasingly popular option with proposed superior results. Our study aims to evaluate the results among a population of active elderly patients with displaced fractures managed with either cast immobilization or internal fixation with volar locking plate. Seventy-five patients (35 cast immobilization and 40 internal fixation) with mean age of 74 ± 7.5 years with minimum of 12 months follow-up were studied. The radiological and clinical parameters were assessed at three, six, and 12 months. Functional outcomes (DASH, Green-O'Brien) were assessed at 12 months. Patients who underwent surgery regain wrist motion and grip strength earlier, but this was not statistically significant after six months.

Early results of combined palmar-dorsal scapholunate ligament reconstruction.

Isolated dorsal scapholunate reconstruction may be inadequate to stabilize and restore physiological scapholunate kinematics in the setting of combined dorsal and palmar ligamental incompetence. To address this entity, a combined reconstruction that encompass both dorsal and palmar scapholunate reconstruction was performed in 20 patients followed up to 19.8 (6-84) months. Compared to the contralateral wrist, the results were extension (67 ± 1.6 to 85.7%, p < 0.01), flexion (84.5 ± 3.2 to 81 ± 2.3%, p = 0.38), grip strength (62 ± 1.6 to 88.3 ± 1.9%, p < 0.01), and pain score (rest: 1.55 ± 0.26 to 0.2 ± 0.09, p < 0.01; activity: 3.2 ± 0.09 to 0.4 ± 0.17, p < 0.01). Based on Mayo wrist score, five excellent, 13 good, and two fair results were reported.

Mechanical failure of the distal radius volar locking plate.

PURPOSE: To review 9 cases of mechanical failure of the volar locking plate for distal radial fractures. METHODS: Records of 374 consecutive patients who underwent volar locking plating for distal radial fractures were reviewed. Mechanical failures of the volar locking plate were defined as plate breakage or bending, screw breakage or loosening, or collapse of articular fragments resulting in intra-articular screw extrusion. RESULTS: Nine mechanical failures occurred between 2 weeks and 3 months in 8 (2.4%) of the patients aged 25 to 82 (median, 74) years with AO fracture types of A3 (n=4), C1 (n=1), C2 (n=1), and C3 (n=3). Mechanical failures included screw pullout (n=5), locking plate bending (n=2), locking screws breakage (n=1), and loosening of locked variable angle screws (n=1). One patient underwent revision of fixation and 2 underwent implant removal. The remainder were treated conservatively. All patients were followed up for a minimum of 12 months; their mean flexion arc was 87 degrees (standard deviation [SD], 17) and the mean rotation arc was 136 degrees (SD, 29 degrees). According to the Green and O'Brien score, their outcomes were good (n=1), fair (n=4), and poor (n=3). CONCLUSION: Although mechanical failure of volar locking plate is uncommon, some are potentially preventable.

Bipedicled homodigital neurovascular island flap for resurfacing dorsal digital defects amputation.

Critical defects distal to the proximal interphalangeal joint are usually treated by heterodigital or reverse-flow homodigital flaps. Drawbacks of the former are potential donor digit stiffness and scarring, while the latter might be complicated by flap congestion. A bipedicled neurovascular island transposition flap design that preserves both proximal and distal extent of digital nerve and artery was employed to treat critical dorsal skin defect in two patients with encouraging results. Technical details and cadaveric study concepts are presented.

Osteocutaneous VY flap to preserve length in coronal oblique fingertip amputation.

Radial or ulnar oblique amputations treated by nailbed levelling and local digital flap reconstruction can result in significantly shortened fingertip, narrowed pulp and nail shape distortion. A VY type flap containing bone, sterile matrix, and skin was conceptualised to restore nail and pulp contour for coronal oblique amputations. Technical details and a clinical case are discussed.

Safe and easy method to preserve fingertip contour in VY-plasty.

VY-plasty is a well-known technique to reconstruct fingertip defects. A simplified method combining pinning of flap and healing of donor site by secondary intention is described. These steps preserve the rounded appearance of the fingertip and restore the convexity of the hyponychium. Flap ischemia due to suture-line tension is also averted.

Surgical hand antisepsis-a pilot study comparing povidone iodine hand scrub and alcohol-based chlorhexidine gluconate hand rub.

INTRODUCTION: The surgeon uses different methods of surgical hand antisepsis with the aim of reducing surgical site infections. To date, there are no local studies comparing the efficacy of iodine hand scrub against newer alcohol-based hand rubs with active ingredients. Our pilot study compares a traditional aqueous hand scrub using 7.5% Povidone iodine (PVP-I) against a hand rub using Avagard: 61% ethyl alcohol, 1% chlorhexidine gluconate. The outcome measure is the number of Colony Forming Units (CFU) cultured from 10-digit fingertip imprints on agar plates. MATERIALS AND METHODS: Ten volunteers underwent 2 hand preparation protocols, with a 30-minute interval in between-Protocol A (3-minute of aqueous scrub using PVP-I) and Protocol B (3-minute of hand rub, until dry, using Avagard). In each protocol, fingertip imprints were obtained immediately after hand preparation (t(0)). The volunteers proceeded to don sterile gloves and performed specific tasks (suturing). At one hour, the gloves were removed and a second set of imprints was obtained (t(1)). RESULTS: Four sets of fingertip imprints were obtained. All 10 participants complied with the supervised hand preparation procedures for each protocol. CFUs of initial fingertip imprints (t(0)): The median CFU counts for initial imprint was significantly higher in the PVP-I treatment (median = 6, Inter Quartile Range (IQR) = 33) compared to the Avagard treatment (median = 0, IQR = 0, P <0.001). CFUs of fingertip imprint at 1 hour (t(1)): The median CFU counts for second imprint (t(1)) was significantly higher in the PVP-I treatment (median = 0.5, IQR = 11) compared to the Avagard treatment (median = 0, IQR = 0, P = 0.009). Our results suggest that the Avagard was more efficacious than aqueous PVP-I scrub at reducing baseline colony counts and sustaining this antisepsis effect. CONCLUSION: Alcohol hand rub with an active compound, demonstrated superior efficacy in CFU reduction. Based on our results, and those pooled from other authors, we suggest that alcohol-based hand rubs could be included in the operating theatre as an alternative to traditional surgical scrub for surgical hand antisepsis.