The Journal of Hand Surgery (Asian-Pacific Volume)

Background: Community Acquired Methicillin Resistant Staphylococcus aureus (CA-MRSA) rates have been increasing worldwide and contribute to a growing “global health security threat” as reported by the WHO. Our group previously reported an overall rate of 7% in CA-MRSA upper extremity infections between 2004–2009 at the Auckland Regional Hand Unit. This fell below the Center for Disease Control (CDC) recommendation for empiric antimicrobial cover once local rates exceed 10–15%. We examined prevalence and characteristics of CA-MRSA upper extremity infections in our region over a subsequent 5-year period.

Methods: One thousand two hundred and fifty-two patients with upper extremity infections requiring operative management between 2011 and 2015 inclusive were included in this study. Associated clinical characteristics were recorded including ethnicity, cultured organisms, antibiotic sensitivities, infection rate, and treatment practice.

Results: One hundred and fifty (12%) of patients had culture positive CA-MRSA upper extremity infections. There was an increasing annual trend. Of note, rates of CA-MRSA in the Maori and Pacific Island ethnic subpopulations exceeded 15% in 2014 and 2015. Susceptibilities, associated factors and patient demographics are reported.

Conclusions: Our unit enjoys significantly lower rates of CA-MRSA upper extremity infections than has been reported internationally. However, trends are increasing relative to our prior 6-year report, and the threshold for empiric treatment has been met within the Maori and Pacific Island ethnic subpopulations. This evolving threat is also highlighted by increasing cases of multi-drug resistant CA-MRSA. Evolving regional guidelines for empiric coverage of CA-MRSA among high-risk ethnic subpopulations identified by this study are underway.

Background: Management of grade III injuries of the radial collateral ligament (RCL) of the thumb is controversial. These injuries are often treated with early surgery. However, early surgery may not be practical for the professional athlete. We report on the outcome of delayed primary repair of chronic RCL injuries without the use of tendon grafts or tendon transfers.

Methods: Twelve elite professional athletes with 15 soft tissue RCL injuries who underwent delayed surgery (greater than 6 weeks) were included in this study. Athletes were managed with splinting and ongoing play during the sporting season, and underwent surgery at the conclusion of the season. Mean duration from injury to surgery was 5 months. Mean follow-up was 4.2 years after surgery. Patient-report outcome measures including pain, satisfaction rating, and disability of the arm, shoulder and hand (DASH) scores were collected. Examination findings including range of motion, laxity, and grip and pinch strength were also measured. Return-to-play data were collected for all athletes.

Results: The RCL was able to be primarily repaired with suture anchors in all cases. All twelve patients were able to return to competitive play at the same pre-injury professional level. Post-operative joint function such as range of motion and laxity were comparable to the unaffected contralateral side, as were grip and lateral pinch strengths. Tip-pinch strength is lower compared to the unaffected side, but is comparable to age and sex-matched reference group.

Conclusions: Delayed primary repair of the RCL is a viable option and results in satisfactory long-term outcomes. This option may be more preferable to the professional athlete who wishes to avoid surgery during the sporting season.

Background: Night time numbness is a key characteristic of CTS and relief of night time symptoms is one of the outcomes most important to patients. This study tested the null hypothesis that there is no difference between sleep quality and night symptoms before and after carpal tunnel release (CTR).

Methods: Forty-four, English-speaking adult patients requesting open CTR for electrodiagnostically confirmed carpal tunnel syndrome completed questionnaires before and after surgery. Average age was 59, 24 patients were men and 20 were women. Patient with a primary or secondary sleep disorder were excluded. Before surgery, patients completed the Pittsburg Sleep Quality index (PSQI). At an average of 3 months after surgery, participants completed PSQI questionnaires. Onset of sleep quality improvement was specifically addressed. Differences between preoperative and postoperative sleep quality were evaluated using the paired t-test. Spearman correlations were used to assess the relationship between continuous variables.

Results: Of the 44 patients, 32 (72%) were classified as poor sleepers (PSQI > 5.5) prior to surgery. At 3 months follow up, there was a significant improvement PSQI global scores (7.8 ± 5.1 vs 4 ± 3.5, p < 0.001) as well as subdivisions. Daytime dysfunction (0.2 ± 0.4, p < 0.001) and medication use (1.0 ± 1.2 vs 0.9 ± 1.2, p < 0.045) secondary to sleep disturbance and was improved as well. In all patients, onset of improvement was within 24 hours of surgery.

Conclusions: CTR is associated with improvement in sleep quality at 3 months follow-up. CTR improves daytime dysfunction related to the sleep disturbance. The onset of sleep improvement is 24 hours after surgery in most cases.

Background: The upper limb surgery under the ultrasound-guided brachial plexus block is becoming popular due to its safety, effectiveness, and convenience. However, the uneven distribution of anesthesiologists become a social problem. Ultrasound-guided brachial plexus block by surgeons has been widespread especially in hand surgeons. We report the surgical treatment of distal radius fractures under the ultrasound-guided brachial plexus block performed by surgeons in our hospital.

Methods: The subjects were 101 patients (41 males and 60 females, average age 61.6 years) who underwent surgery for distal radius fractures under ultrasound-guided brachial plexus block administered by orthopedists at our university or related facilities between January 2014 and June 2016. Brachial plexus block was administered through the supraclavicular approach. The time from initiation of anesthesia to initiation of surgery, mean operative time, the presence or absence of additional anesthesia (local infiltration anesthesia, intravenous anesthesia, and general anesthesia), and complications were evaluated.

Results: The mean time from brachial plexus block to initiation of surgery was 35.7 (20–68) minutes, and the mean operative time was 90.5 (35–217) minutes. Surgery was completed with brachial plexus block alone in 62 patients (61.4%), and additional anesthesia was necessary in 39 patients (38.6%). Furthermore, general anesthesia was employed in 6 patients (5.9%). No serious complications occurred.

Conclusions: According to our results, the operation could be completed with brachial plexus block alone and additional local infiltration anesthesia or intravenous anesthesia in 94.1% (95 cases). However, 6 cases (5.9%) shifted to general anesthesia. Although it needs training, we consider that hand surgery including distal radius fractures treatment under the ultrasound-guided brachial plexus block is possible. On the other hand, cooperation or a cooperative system with anesthesiologists is necessary for surgeons to administer this anesthesia.

Background: Patients with advanced osteoarthritis of the first carpometacarpal joint (CMC-1) may develop hyperextension of the first metacarpophalangeal joint (MCP-1). No clear clinical benefice has been reported consecutively to the surgical treatment of the MCP-hyperextension combined to a trapeziectomy. The reason of the missing benefit may be due to changes in the thumb position impairing the thumb stability secondary to the surgical procedures. We assessed changes in the transmission of forces at the thumb’s end phalanx following a trapeziectomy combined with the surgical adjustment of the hyperextension of the MCP-1-joint in a biomechanical investigation using cadavers.

Methods: The thumb muscles were loaded with nylon cables connected to a tension meter in 8 forearm cadavers. A 6-axis force sensor assessed the termino-lateral key-pinch orthogonal strength vectors at the level of the thumb distal phalanx prior to any surgery, and following a simple trapeziectomy, a trapeziectomy combined to a MCP-1-capsulodesis and the transfer of the extensor pollicis brevis over the metacarpal-1 head, or to an MCP-1-arthrodesis.

Results: Combination of the trapeziectomy with the MCP-1- joint palmar capsulodesis and EPB-transfer or with a MCP-arthrodesis in neutral pronation-supination resulted in a significant shift of the thumb in pronation-abduction with respect to the preoperative assessment. The lowest shift was achieved when performing the arthrodesis in 20° supination or by overloading of the adductor pollicis.

Conclusions: Combining the trapeziectomy with surgeries addressing the MCP-1-joint hyperextension induced a shift of the thumb in pronation-abduction that could impair the key-pinch stability. When considering additional procedures for MCP-1-joint hyperextension deformities, it should be recommended to fix the EPB-tendon on the radial aspect of the metacarpal head if a tendon transfer is considered, otherwise the MCP joint arthrodesis should be performed in supinated position, in order to achieve lateral key-pinch stability.

Background: Flexor tendon repair carries a significant risk for complications, which often leads to revision surgery. The purpose of this study was to assess the effect of different factors on the risk for major complications patients undergoing a primary end-to-end flexor tendon repair and early passive mobilization regimen (Kleinert protocol).

Methods: Between January 2000 and September 2009, a total of 312 patients underwent a flexor tendon repair at out institution. We excluded patients whose injury was self-inflicted or secondary to a rheumatic disease or a fall leaving 187 patients with 325 injured tendons for the study.

Results: 152 (81.7%) patients were male and 34 (18.3%) females. Mean age of the patients was 32.7 years (SD 14.4, range 11 to 73). The fifth ray was most commonly affected. The majority of the injuries were located in zone II. Median delay to surgery was 3 days. Complications were observed in 34 patients (18.2%). Univariable analysis showed that patient age, mechanism of injury, injured ray, delay to surgery between three and seven days, and greater suture thickness were associated with increased risk of complications. In the subsequent multivariable analysis, only the mechanism of injury and delay to surgery remained as significant risk factors for major complications.

Conclusions: We conclude that complications after flexor tendon repair may be reduced by appropriate timing of the surgery. Delay to surgery lasting between three and seven days seems to be associated with increased risk for major complications.

Background: The interaction between wrist kinematics and synovial fluid pressure has yet to be studied. To our knowledge, this is the first study to determine the effect of scapholunate joint kinematics on synovial fluid pressure change using finite volume method.

Methods: The carpal bones of a cadaveric hand were obtained from Computed Tomography (CT) scans. CT images of the carpal bones were segmented and reconstructed into 3D model. The 3D synovial fluid model between the scaphoid and lunate was constructed and then used for computational simulations. The kinematics data of scapholunate joint obtained from radioulnar deviation of the wrist was investigated.

Results: It was found that the pressure in synovial fluid varied from -1.68 to 2.64 Pa with maximum pressure located at the scaphoid-fluid interface during the radial deviation. For ulnar deviation, the pressure increased gradually from the scaphoid-fluid interface towards the lunate-fluid interface (-1.37 to 0.37 Pa).

Conclusions: This new computational model provides a basis for the study of pathomechanics of ligament injury with the inclusion of synovial fluid.

Background: Asymptomatic, incidental extensor carpi ulnaris (ECU) tendon abnormalities are frequently noted on imaging studies of the wrist. The aim of this investigation was to determine if variations in gross tendon anatomy existed that could possibly account for these findings on MRI and ultrasound (US) imaging.

Methods: The upper extremities of eleven (6 male and 5 female) formalin preserved cadavers were dissected and examined under loupe magnification with attention to the dorsal-ulnar wrist and hand and the ECU tendon. The tendons were inspected for anatomic variations, degenerative changes, and any other pathologies. The presence of intra-tendinous splits arising within the ECU tendon was noted and measured. The distances of the splits from the distal tendon insertion and the edge of the extensor retinaculum were recorded. Statistical correlations between age and the tendon splits were considered using R-squared to assess a linear regression.

Results: 17 ECU tendons were dissected and examined, and 5 ECU tendons were excluded due to poor preservation of that upper extremity; all five were right sided upper extremities. Eleven of the 17 specimens demonstrated at least one split in the distal tendon: Seven had 1 split, 1 had 2 splits, and 3 had 3 splits. The mean length of the tendon split was 3.52 cm. The mean distance of the distal edge of the split to the tendon insertion site was 2.4 cm. A linear regression was calculated and showed no correlation between age and number of tendon splits.

Conclusions: 64% of specimens showed a longitudinal split in the distal ECU tendon. The location of these frequent splits corresponds to imaging abnormalities on MRI and US in prior studies.

Background: When closed ruptures of flexor tendons of fingers occur, there is often an identifiable pathology, which should be addressed in the same surgical setting as the tendon repair. The concept of “spontaneous” tendon rupture, occurring in the absence of identified pathology, however, has also been reported in a significant number of papers. This controversy has prompted us to do a review of the existing literature.

Methods: We did a review of cases of closed ruptures of the flexor digitorum profundus (FDP) of the little finger in existing literature. Fifty-three publications were retrieved by searching “FDP tendon rupture” and “little finger” using PubMed database. We analyzed data such as the zone of rupture noted intra-operatively; and any precipitating factors, pathology or trauma. We also conducted a review on papers which discussed the concept of “spontaneous rupture”.

Results: Fifty-three publications were retrieved. There were 8 cases of ruptures in Zone I; 2 in Zone II; 30 in Zone III; 59 in Zone IV and 5 in Zone V. Majority of cases were associated with an element of trauma of varying severity, or pathology. A precipitating cause was not documented in 12 cases. Amongst all 36 cases of ruptures labelled as “spontaneous”, only 1 case was truly “spontaneous” without any associated trauma or pathology.

Conclusions: Most reports labeled as spontaneous rupture occurred in Zone III, where tendon ruptures are rare. There are documented pathological causes or evidence of trauma to most of these cases. We conclude these ruptures may have been mislabeled as spontaneous ruptures. Bearing in mind the propensity for tendon excursion, we suspect the lack of documentation of exploration in proximal zones contributed to this mislabeling. Understanding this concept of non-spontaneity to most tendon ruptures and the common sites of rupture or pathology is crucial for a surgeon to make strategic incisions and minimize future recurrence.

Background: Hand and upper limb soft tissue infections result in significant disability and loss of productivity. Many infections have been shown to follow a seasonal variation, however little is known about this is the context of upper limb soft tissue infections. We aimed to evaluate seasonal variation in acute bacterial, hand and upper limb skin and soft-tissue infections, and correlate findings with key environmental variables.

Methods: Hand and upper limb soft tissue infection cases from 2006–2016 were retrieved from a single UK center. Cases were reviewed for microbiology culture and sensitivity. Correlation between cases and season, temperature and humidity was assessed.

Results: 206 cases were identified for inclusion. Specimens were sent for microbiology in 76.4% of cases. Of these 78.9% were culture positive, 47.6% exhibited antibiotic resistance and 16.9% were multi-resistant. There was a significant difference between season and culture positive cases, with significantly more culture positive cases in the summer vs. winter on post-hoc analysis (p = 0.004). There was a significant positive correlation between higher temperatures and number of culture positive cases (r = 0.75). There was no significant correlation between temperature and antibiotic resistance (r = 0.5) or between humidity and culture positive cases (r = −0.42).

Conclusions: This study demonstrates a seasonal variation in hand and upper limb infections, with a significant correlation between infection rates and ambient temperature. Appreciating seasonal variability of these infections could prove beneficial for surgical planning, public health recommendations and antibiotic guidelines. However, further international data is needed to understand potential mechanisms involved.

Background: Chronic, post-traumatic, avulsion of the proximal interphalangeal (PIP) joint volar plate represents a disabling lesion. The purpose of this report is to describe a flexor digitorum superficialis (FDS) tenodesis using a mini-bone anchor inserted into the proximal phalanx, and its clinical outcome.

Methods: 15 patients with chronic post-traumatic hyperextension instability of the PIP joint were treated surgically. From the first post-operative day patients were invited to start an early gradual joint active motion, wearing an extension block splint. Forty days after surgery, clinical evaluations were carried out, including: joint stability, pain and range of motion (ROM). The use of a circumferential splint was recommended for two further months, avoiding strenuous manual activities. The range of motion, time lost at work and the functional results were recorded six months after surgery.

Results: At last follow up, 7 of the 13 reviewed patients presented an excellent functional recovery, with complete resolution of pain and stability with attainment of ROM comparable to the contralateral finger. The others 6 patients obtained good results, with remission of the functional impairment and pain, with either residual hyperextension or flexion contracture. There was one case of recurrence consecutively to a premature traumatic work-related activity.

Conclusions: The FDS tenodesis via a bone anchor, combined with early active PIP joint protected motion, was shown in this study to be effective and reliable.

Background: The failure of scaphoid reconstruction by restoring both length and shape may lead to carpal mal-alignment and progressive degenerative arthritis. The aim of our study is to find a reliable method to find out the scaphoid length without measuring the contralateral scaphoid.

Methods: Three X-ray wrist views were collected for 51 patients without any signs suggesting any hand and wrist fractures. The scaphoid, capitate and 3^rd metacarpal bone axes lengths and carpal height were measured by 4 hand surgeons separately.

Results: The scapho-capitate ratio was 1.1 ± 0.084, 1.01 ± 0.084 and 0.92 ± 0.109 for lateral, postero-anterior with ulnar deviation and postero-anterior view respectively. The ulnar deviation view had the highest reliability.

Conclusions: Scapho-capitate ratio estimation is an easy and accurate measure of normal scaphoid length in situations when the scaphoid is short. It is helpful for the estimation of the size of the bone graft that need for reconstruction of the scaphoid.

Background: The tendon of the plantaris muscle (PM) is highly relevant in surgical practice. It is used as a graft for tendon/ligament repair or reconstruction in hand surgery whenever palmaris longus (PL) is lacking. Its occurrence in humans is reported to be high.

Methods: A meta-analysis based on cadaveric studies was conducted to quantitatively assess PM frequency and size.

Results: Data from 41 studies including 10062 leg specimens yielded the following: overall true prevalence ≈ 93%, overall crude prevalence = 90.6%, bilateral prevalence ≈ 92%, significantly more frequent on the right side, no gender significance, and no significant differences between ethnicities except that of Brazilian populations. The pooled mean length (± SD) of the PM tendon (PT) was 30.63 ± 5.87 cm and that of its width was 3.68 ± 1.37 mm. Pooled frequencies of the types of PT insertion are reported.

Conclusions: This meta-analysis demonstrated a higher prevalence of PM when compared to clinical PL frequency in the literature with a tendon length double than that of PL along with an acceptable width. The surgical availability of the PM tendon was found stable across human populations; a clinical advantage when compared to the high variability of PL ethnicity-based frequency. Our results indicate that the PT is of high clinical relevance as a reliable and suitable resource for tendon grafting and reconstruction.

Background: The preferable reconstructive surgical options for Allen type IV finger amputation is replantation. The viable alternate option is bone and nail bed graft repositioning on local flaps. The wider scope of this “graft reposition on flap” (GRF) technique was introspected.

Methods: Fifteen patients who sustained type IV amputations of finger tip were operated between 2013 and 2017 by GRF technique. The results, range of motions, functional out come and its feasibility were analyzed and evaluated. A technical modification of GRF was also described within this series of patients.

Results: All patients had good nail bed survival and well settled local flaps. Static two-point discrimination (2PD) was of 6.4 mm (average). 14/15 patients had an acceptable shortening of 4mm (average). Overall patients were happy after surgery and returned back to their work. All had excellent range of movements and 0 VAS. The follow up was 1 to 5 years (mean 2.8 years). Wound infection was seen in one patient whom after debridement developed gross shortening and thick nail. None developed nail deformity.

Conclusions: The GRF provided an alternative option for Allen type IV amputations of finger tip. It can be well executed in all reconstructive surgical units and in those with a learning curve for replantations surgeries. The results of GRF were proportionate with the available surgical options in terms of appearance, function and outcomes.

Background: Closed mini-wrist transverse incision for carpal tunnel release has been reported in decreasing surgical scar problems, but there were few cadaveric studies that proved the effectiveness and safety in this technique without protective instrument to the median nerve. Hydro-dissection was previously showed to separate median nerve and deep structures during percutaneous ultrasound guided transverse carpal ligament release. This cadaveric study aims to demonstrated effectiveness and safety of closed transverse carpal ligament (TCL) release though the mini-transverse incision at distal wrist crease combined with hydrodissection technique. Neither special instrument nor retractor was used to protect neurovascular structures.

Methods: Twelve fresh frozen cadaveric wrists were included in this study. Completeness of TCL release and injury to the adjacent neurovascular structures were assessed by direct visualization. Thickness of TCL, TCL length and distance from incision to adjacent neurovascular structures were also recorded.

Results: Complete release of TCL was demonstrated in all 12 (100%) wrists underwent the mini-transverse incision TCL release at distal wrist crease and hydro-dissection technique. No injury to the adjacent neurovascular structures was found in all 12 wrists. Mean of thickness of TCL and TCL length were 3 mm and 28.7 mm, respectively. The ulnar artery was the nearest structure to the incision (mean = 3.7 mm).

Conclusions: The closed mini-transverse incision TCL release at distal wrist crease with hydro-dissection technique demonstrated completeness of TCL division and safety to the neurovascular structures without protecting retractor or special instrument.

We report a patient of Scapholunate (SL) injury in which radiography revealed obvious SL dissociation with dorsal intercalated segment instability deformity, but arthroscopy showed a SL gap of less than 2 mm. Radiographs of the uninjured wrist showed a SL interval of 3.0 mm and a SL angle of 80°. Preoperative magnetic resonance imaging showed low signal intensity in the proximal portion of the scaphoid and a mild SL gap on T1-, T2-weighted, and T2-weighted fat-suppressed images. Midcarpal wrist arthrography revealed a small amount of contrast media leakage through the SL interval. It was considered that incomplete ossification of the scaphoid mimicked obvious radiographic SL dissociation.

A relatively rare tumor, osteoid osteoma most commonly affects the lower extremity. In 10% of the cases, it can affect the hand and wrist. We present a case of osteoid osteoma in the proximal phalanx of ring finger that was initially misdiagnosed as a soft tissue lesion. The soft tissue lesion was resected, but the symptoms recurred shortly thereafter, leading to repeat diagnostic workup. Despite X-rays, magnetic resonance imaging, and tissue biopsy, the diagnosis remained elusive until surgical re-exploration. Based on the lessons learned from this case and the experience reported in literature, we discuss the intricate nature of osteoid osteoma diagnosis in the hand, the obstacles often encountered, and how to approach these challenging patients in a stepwise and critical fashion.

The anatomic variations of the median nerve and of the muscles of the wrist have been widely reported in literature. It is essential for the surgeon to be familiar with these variations in order to avoid accidental injury to the nerve during surgery. We report a rare case of bifid median nerve accompanied by an anomalous tendon of palmaris profundus discovered during the surgical release of carpal tunnel. The transverse carpal ligament was dissected and the anomalous tendon was left in situ because any direct compression over the median nerve was noticed intraoperatively. The patient was evaluated one year postoperatively clinically and radiologically (with MRI). At the follow up the resolution of symptoms was complete and the sleep disturbance was solved. The patient achieved a postoperative QuickDASH score of 9.1 and a Michigan Hand Questionnaire outcome score of 90 points.

Carpal bone fracture-dislocation is an uncommon wrist injury. Regarding limited prevalence of such injury, most of orthopedic surgeons have low experience in treatment and handling of these fractures and dislocations. A 25-year-old male worker with an uncommon carpal bone fracture-dislocation, namely bilateral scaphocapitate fracture syndrome, was described. Volar and dorsal approaches were used for reduction and fixation; complete stabilization was achieved after open reduction and fixation using Herbert screws into scaphoid and capitate. A 5-year follow-up showed satisfactory functional and radiographic results. In the case of scaphocapitate fracture syndrome open reduction and internal fixation by compression screws (rather than inserting multiple pins) leads to complete union in scaphoid and capitate. Restoration of normal anatomy in carpus bones can result in long-term satisfactory functional results while preventing possible complications.

We encountered a case of capitellum fracture with radial head dislocation in which it was challenging to diagnose whether the dislocation was coincident with the fracture or this was chronic dislocation that presented before the fracture. Chronic radial head dislocation may be congenital or could occur in patients with untreated post-traumatic dislocation, although diagnosis is particularly challenging if the radial head dislocation is unilateral. Classical capitellum fracture involves anterosuperior bone fragment dislocation. However, in the present case, the bone fragment was present beneath the radial head, which suggests chronic radial head dislocation. When the bone fragment appears in a different position than usual, every effort should be made to understand the pathophysiology by reviewing the mechanism of onset, disease history, and imaging.