Kinematic analysis of the scaphoid using gated four-dimensional CT.

AIM: To investigate the kinematics of the scaphoid while the wrist was in radioulnar motion using gated four-dimensional computed tomography (4DCT) imaging. MATERIALS AND METHODS: Six cadaveric wrist specimens were scanned in the following order of capsulotomy and ligament sectioning: (1) ligaments intact, (2) capsulotomy, (3) scapholunate ligament division, and lastly, (4) lunotriquetral ligament division. A three-dimensional model was then reconstructed to analyse the translation and angular displacements of the scaphoid. RESULTS: The magnitude of displacement was found to increase with each consecutive ligament sectioning. Translation along the y-axis was statistically significant, with the scaphoid shifting up to 1.39 mm from its original position after complete sectioning of the ligaments while the wrist was deviating radially. Angular displacement about all three axes was statistically significant, with the highest occurring in the flexion-extension plane when the scaphoid flexed by 9.1° from its original position after total sectioning of the ligaments. CONCLUSION: The present study showed that changes in the kinematics of the scaphoid can be detected using 4DCT, thus demonstrating its feasibility in the diagnosis of dynamic carpal instability, which only presents during motion.

Interfragmentary compression profile of 4 headless bone screws: an analysis of the compression lost on reinsertion.

PURPOSE: To evaluate the interfragmentary compression force generated by 4 different types of headless compression screws and to examine the effects of removal and reinsertion of the screw. METHODS: We chose foot bones rather than scaphoids for the model because they were larger and would enable comparison of 2 screw designs in the same bone, thereby controlling for the effect of interspecimen variability. A transverse osteotomy was made in 10 fresh-frozen cadaveric navicular bones and 10 medial cuneiforms. A load cell was used to measure compression between the 2 fragments as a screw was inserted across the fracture. Each bone was tested twice, with an Acutrak Mini (Acumed, Hillsboro, OR; n = 10) and an SBi AutoFIX screw (SBi, Morrisville, PA; n = 10) or an Extremifix (Osteomed, Addison, TX; n = 10) and a Barouk screw (Depuy, Warsaw, IN; n = 10). Compression was recorded at initial insertion and on removal and reinsertion of the screw twice to the same position. Compression was also measured after one additional full turn further than the initial position. RESULTS: The mean interfragmentary compression generated by the Acutrak Mini screw was greater than that of the SBi AutoFIX screw (96 N vs 22 N). There was a trend toward a greater mean compression generated by the Extremifix screw compared to the Barouk screw (85 N vs 22 N). There was a significant loss of compression upon removal and reinsertion of the screws. An additional full turn of the screw was able to re-establish a large proportion of the original compression. CONCLUSIONS: The compression forces achieved by headless screw systems appeared to vary according to the screw design, depth of insertion, and the quality of the bone. Substantial compression was lost if the screw was removed and replaced. Some screw designs appeared to require a greater depth of insertion to achieve effective compression, and the number of additional turns required to re-establish compression might vary according to the thread design. CLINICAL RELEVANCE: Surgeons should be aware of the compression profile of each screw design and the effect of screw removal and reinsertion in the clinical setting of small bone fixation.

The Effect of Intra-carpal Kirschner Wire Augmentation in Screw Fixation of Scaphoid - A Retrospective Cohort Study.

INTRODUCTION: Scaphoid fractures are most often treated with a single headless compression screw. However, intercarpal Kirschner wire (K-wire) might be added to improve stability and fracture outcomes. This study will determine if there is a difference in treatment outcome (union rate and time to union) between scaphoid fracture fixations using a single headless compression screw with and without augmentation using a intracarpal intramedullary K-wire. MATERIAL AND METHODS: We conducted a retrospective review of patients who underwent surgery for isolated scaphoid fractures over a 15 years period from December 2000 to December 2015. Only patients who underwent open surgery with bone grafting were included. They were divided into a group treated with a single screw fixation, and another group treated with screw and K-wire fixations. RESULTS: Forty-four (58.7%) patients had single screw fixation and 31 (41.3%) had screw augmented with K-wire fixation. The overall union rate was 88.0%, with an overall mean time to union of 5.3 months. There was no difference in union rate (p=0.84) and time to union (p=0.66) between the single screw group and combined screw and K-wire group. Univariate analysis found that older age (t=-2.11, p=0.04) had a significant effect on union rate. Regression model showed that age had a significant effect on months to union. CONCLUSION: In open fixation of scaphoid fractures with compression screw and bone grafting, union rate and time to union is comparable whether or not screw fixation was augmented with an intracarpal K-wire. There was no increased risk of complications associated with augmented screw. Age of patient affected time to union and union rate.

Use of dorsal buttress plate fixation for ulnar carpometacarpal joint fracture dislocations for early mobilization: outcomes of 11 cases.

AIM: This study reviews the surgical outcomes of using dorsal buttress plate for open reduction and internal fixation of ulnar (5th, or 4th and 5th) CMCJ fracture subluxation or dislocations. METHODS: A retrospective review of 11 patients at our center who underwent operative fixation with dorsal buttress plating technique was performed. The surgery was performed between February 2012 and March 2017. Outcome measurements include radiographic evaluation of time to union, grip strength, and range of motion of the wrist. RESULTS: Of 11 patients in our case series, eight had injuries involving both 4th and 5th CMCJs, while three had isolated involvement of 5th CMCJ. Mean time to union on radiographs was 48 days (IQR 17.0; range 30-88). The median palmar flexion and dorsiflexion of the wrist were 56° (IQR 11.3; range 50°-80°) and 65° (IQR 10.0; range 60°-80°) respectively. Patients regained a median of 79% of grip strength (IQR: 36.0, range 43-100). All fingers achieved full range of motion, and no patient had scissoring of the fingers. Two patients had temporary mild numbness over the dorsoulnar aspect of the hand in the region of the 4th webspace. Five patients underwent removal of implants due to plate breakage (n = 2), or mild pain or pain with cold (n = 3). All patients were well after plate removal, and all the patients with pain had resolution of pain after implant removal. CONCLUSION: The dorsal buttress plate is a viable option for fixation of ulnar CMCJ fracture dislocations to allow early mobilization.

Effect of interfragmentary gap on compression force in a headless compression screw used for scaphoid fixation.

We investigated the effect of an interfragmentary gap on the final compression force using the Acutrak 2 Mini headless compression screw (length 26 mm) (Acumed, Hillsboro, OR, USA). Two blocks of solid rigid polyurethane foam in a custom jig were separated by spacers of varying thickness (1.0, 1.5, 2.0 and 2.5 mm) to simulate an interfragmentary gap. The spacers were removed before full insertion of the screw and the compression force was measured when the screw was buried 2 mm below the surface of the upper block. Gaps of 1.5 mm and 2.0 mm resulted in significantly decreased compression forces, whereas there was no significant decrease in compression force with a gap of 1 mm. An interfragmentary gap of 2.5 mm did not result in any contact between blocks. We conclude that an increased interfragmentary gap leads to decreased compression force with this screw, which may have implications on fracture healing.

Long-term outcome of carpal tunnel release surgery in patients with severe carpal tunnel syndrome.

AIMS: Few studies have examined the long-term outcome of carpal tunnel release (CTR). The aim of this study was to evaluate the patient-reported long-term outcome of CTR for electrophysiologically severe carpal tunnel syndrome (CTS). PATIENTS AND METHODS: We reviewed the long-term outcome of 40 patients with bilateral severe CTS who underwent 80 CTRs (46 open, 34 endoscopic) between 2002 and 2012. The outcomes studied were patient-reported outcomes of numbness resolution, the Boston Carpal Tunnel Questionnaire (BCTQ) score, and patient satisfaction. RESULTS: The mean follow-up was 9.3 years. Complete resolution of numbness was reported by 93.8% of patients, persistent numbness by 3.8%, and recurrent numbness by 2.5%. The mean BCTQ symptom score was 1.1 (sd 0.3; 1.0 to 2.55) and the mean Boston function score was 1.15 (sd 0.46; 1.0 to 3.5). 72.5% of patients were asymptomatic and had no functional impairment. Men had poorer outcomes than women and patients < 55 years had poorer outcomes than patients ≥ 55 years. All patients who had undergone endoscopic CTR reported complete resolution of numbness compared with 89.1% of those who had undergone open release (p = 0.047). There was no significant difference in outcome between dominant and non-dominant hands. Patient satisfaction rates were good. There were no adverse events. CONCLUSION: CTR has a favourable outcome and good rates of satisfaction, even in patients with bilateral severe CTS at a mean of nine years after surgery. Endoscopic CTR has a higher rate of numbness resolution than open surgery. There were no significant differences in outcome between the dominant and non-dominant hand. Cite this article: Bone Joint J 2017;99-B:1348-53.

Patient-reported outcomes of carpal tunnel release surgery in patients with bilateral severe carpal tunnel syndrome.

This retrospective study examined whether the presenting complaint of numbness is relieved post-operatively in severe carpal tunnel syndrome and also assessed any correlation between outcomes of the first and second procedures in staged bilateral carpal tunnel releases. Carpal tunnel release (60 open and 38 endoscopic) was done in 49 patients with bilateral severe carpal tunnel syndrome. There was complete resolution of numbness post-operatively in 77% ( n = 75) of hands. The median post-operative time before complete resolution of numbness was 21 days (IQR 8 to 21; range 3 to 482). The likelihood of complete resolution of symptoms after the second carpal tunnel release in patients with complete resolution of symptoms after the first carpal tunnel release was 22 (95% CI: 4 to 131) times that of the likelihood of improvement in patients with incomplete resolution of symptoms after the first carpal tunnel release. LEVEL OF EVIDENCE: IV.

Biomechanical investigation of uneven load bearing in six-strand Lim-Tsai flexor tendon repair using FiberLoop®.

We hypothesized that, in providing biomechanical strength, at least one of the two middle strands in a modified six-strand Lim-Tsai flexor tendon repair could be divided without obvious reduction in repair strength owing to uneven load bearing. A total of 40 porcine flexor digitorum profundus tendons were repaired using the six-strand Lim-Tsai technique with a 4-0 FiberLoop® suture and then divided into four equal groups. (no cut, one middle strand cut, both middle strand cut, one side strand cut). The biomechanical performance of repaired tendons was tested and found to vary according to the location of the cuts.

What triggers in trigger finger? The flexor tendons at the flexor digitorum superficialis bifurcation.

To define the role of the flexor tendons in trigger finger, a high-resolution ultrasound examination was performed in 20 trigger fingers and 20 normal contralateral digits in three digital postures: full extension, mid-flexion and near-full flexion. Precise measurements of diameter and cross-sectional area of the combined tendon mass were recorded at five clearly defined locations: summit of the metacarpal head, proximal lip of the proximal phalanx (PP) and at 1/8, 1/4 and 1/2 length of the PP. In the normal tendons, there was an anatomical thickening, not previously appreciated at 1/4 length PP, in the region of the FDS bifurcation. This anatomical region moved proximally on finger flexion to the A1 pulley. In trigger fingers, the flexor tendons had greater diameter (sagittal view) and cross-sectional area than the normal side at all locations (p < 0.01, p < 0.001), with an even greater increase in diameter in the FDS bifurcation area (p < 0.001). Trigger fingers also had thicker A1 pulleys (p < 0.001). Triggering occurs on flexing the finger when the enlarged combined flexor tendon mass at the specific anatomical region of the FDS bifurcation impacts on the thickened A1 pulley, resisting its excursion.

Biomechanical investigation of 'figure of 8' flexor tendon repair techniques.

This biomechanical study compared the original Al-Qattan repair with other modifications postulated to reduce bulk and friction, thereby potentially improving outcome. A total of 32 cadaveric digits with intact flexor apparatus were used. In each digit, the flexor digitorum profundus and flexor digitorum superficialis tendons were cut cleanly in Zone 2. We tested Al-Qattan's technique along with three modifications using stronger suture material and varying the number of strands across the repair site. Of the four repair techniques, the modified Al-Qattan's technique using two 'figure of 8' 4-0 Fiberwire core sutures (Group 4) had the best balance of ultimate tensile strength (50.9 N), 2 mm gapping force (38 N) and friction. The modified technique provided a stronger repair for early active mobilization and has less friction than the originally described repair.

The prevention of neuroma formation by diathermy: an experimental study in the rat common peroneal nerve.

INTRODUCTION: There have been anecdotal reports of the efficacy of diathermy (electrocoagulation) in the prevention of neuroma formation. However, this has not been investigated in the laboratory. In this experiment involving 40 rats, diathermy was applied to the terminal proximal ends of transected rat common peroneal nerves to evaluate its effect on neuroma formation. MATERIALS AND METHODS: Monopolar and bipolar diathermy set at 45 W, applied for different durations (4 seconds and 10 seconds), were evaluated. Under histological control, the presence of neuroma formation and the diameter of the nerve ends were evaluated at 3 months. The contralateral common peroneal nerve in the same rat served as the control. The dorsal root ganglia of 2 rats in each group were also harvested for histological study. RESULTS: The incidence of neuroma formation was 30% in the group which received high-duration monopolar diathermy (10-second application), versus 90% in the control group (P <0.05). The mean diameter of the nerve ends was smaller at 0.51 mm [standard deviation (SD), 0.29] versus 0.85 mm (SD, 0.24) in the control (P <0.05). The incidence of neuroma formation was 30% in the group which received low-duration monopolar diathermy (4-second application), and 83% in the control group (P <0.05). The diameter was 0.43 mm (SD, 0.14) versus 0.85 mm (SD, 0.28) (P <0.05). High-duration bipolar diathermy applied for 10 seconds, showed a neuroma formation of 25% versus 100% in the control group (P <0.05). The diameter of the nerve ends was 0.48 mm (SD, 0.07) versus 0.79 mm (SD, 0.36) in the control group (P <0.05). The incidence of neuroma formation was 60% in the low-duration bipolar group, which received bipolar diathermy application for 4 seconds, and 90% in the control group (P = 0.25). The diameter of the nerve ends in the low-duration bipolar group was 0.52 mm (SD, 0.24) versus 0.76 mm (SD, 0.40). The incidence of neuroma formation and the difference in diameter in the low duration-bipolar group were both not statistically significant. CONCLUSION: This study demonstrates the effectiveness of monopolar diathermy in reducing the rate of neuroma formation. For bipolar diathermy, an application of 10 seconds was effective in reducing neuroma formation but an application of 4 seconds was not associated with a significant reduction in neuroma formation.

Heterodigital arterialized flaps for large finger wounds: results and indications.

Deep defects of the hand and fingers with an unhealthy bed exposing denuded tendon, bone, joint, or neurovascular structures require flap coverage. However, the location and size of the defects often preclude the use of local flap coverage. Free-flap coverage is often not desirable either, because the recipient vessels may be unhealthy from surrounding infection or trauma. In such situations, a regional pedicled flap is preferable. A solution to this is the heterodigital arterialized flap. This flap is supplied by the digital artery and a dorsal vein of the finger for venous drainage. Unlike the neurovascular island flap, the digital nerve is left in situ in the donor finger, thus avoiding many of the neurologic complications associated with the Littler flap. The digital artery island flap is centered on the midlateral line of the donor finger. It extends from the middorsal line to the midpalmar line. The maximal length of the flap is from the base of the finger to the distal interphalangeal joint. By preserving the pulp and the digital nerve, a sensate pulp on the donor finger remains that reduces donor-finger morbidity and also preserves fingertip cosmesis. Twenty-nine flaps were performed in 29 patients and the outcomes in the donor finger and the reconstructed finger were reviewed. The flap survival was 100 percent. There were no cases of flap ischemia or flap congestion. Good venous drainage of the flap through the additional dorsal vein was helpful in preventing the occurrence of early postoperative venous congestion, which is common in island flaps of the fingers, which depend on only the venae comitantes for drainage. Donor-finger morbidity, measured in terms of range of motion and two-point discrimination in the pulp, was minimal. Ninety-seven percent of the donor fingers achieved excellent or good total active motion according to the criteria of Strickland and Glogovac. Pulp sensation in the donor fingers was normal in 28 of the 29 donor fingers. No cold intolerance of the donor finger or the adjacent finger is reported in this series.

Conservative treatment of redisplaced Colles' fractures in elderly patients older than 60 years old - anatomical and functional outcome.

A retrospective study was carried out to compare the functional outcome in two groups of patients who were 60 years old or older. One group had Colles' fractures, which had been reduced and did not redisplace. The other group's fractures redisplaced and were treated conservatively. Of the 11 patients in the first group, 82% had excellent or good functional outcome, which was not significantly different when compared with the second group of 25 patients with 68% having excellent or good functional outcome.

Intravenous pyogenic granuloma of the hand - a case report.

Intravenous pyogenic granuloma represents a variant of the common pyogenic granuloma in which the capillary proliferation is entirely confined to the lumen of a vein. To our knowledge, this entity is rare and only a few cases have been reported before in the hand. We present a case of intravenous pyogenic granuloma of the hand and a review of this entity from previous published cases.

Self-reported outcome following anterior transposition of ulnar nerve in the elderly.

Cubital tunnel syndrome is a common entrapment neuropathy of the upper limb. This condition can result in significant sensory disturbances and motor deficits in the distribution of the ulnar nerve. Surgical management of cubital tunnel syndrome is indicated when non-operative measures fail. However, in the elderly population, there may be a tendency to avoid surgery as nerve healing has been found to be poor. In our study, we reviewed the results of anterior transposition of ulnar nerve in patients 60 years of age and older. Our results were based on a self-reported outcome at a minimum of one year after surgery - 94.7% of our surgeries resulted in some improvement in symptoms experienced by the patients while there was an overall satisfaction rate of 83.3%. Based on our results, we recommend ulnar nerve transposition in the management of cubital tunnel syndrome in this group of patients if non-operative measures fail.

A split-EPB tendon sling for chronic post-traumatic palmar instability of the thumb metacarpophalangeal joint.

Kessler's extensor pollicis brevis (EPB) palmar tendon sling is a simple and reliable reconstruction for symptomatic palmar instability of the thumb metacarpophalangeal (MP) joint. However, we encountered subluxation of the extensor pollicis longus tendon and extension lag at the MP joint when the entire tendon was used. We modified the technique, splitting the tendon to preserve its function as an MP joint extensor. Six thumb MP joints with anteroposterior instability secondary to hyperextension injury were reconstructed using the split-EPB technique. At an average of 22 months postoperatively, all patients had stable and pain-free MP joints. Pinch strength improved an average of 5.6 kg. MP joint flexion was decreased an average of 17.5 degrees and two patients had flexion contractures of 5 degrees and 20 degrees, respectively. Extensor pollicis longus subluxation and MP extension lag did not occur, and there were no recurrences.