Multi-disciplinary Orthopaedics Rehabilitation Empowerment (MORE) program: A new standard of care for injured workers in Hong Kong

BACKGROUND

The objective of this study is to evaluate the effects of the Multi-disciplinary Orthopaedics Rehabilitation Empowerment (MORE) Program on reducing chronic disability among injured workers and improving efficiency of work rehabilitation process.

METHODS

A cohort of patients with workplace injuries in the lower back were recruited from orthopaedics clinics and assigned to either MORE group (n= 139) or control group (n= 106). Patients in MORE group received an early MRI screening and a coordinated multi-disciplinary management, while patients in the control group received conventional care. Outcome variables are time to return-to-work (RTW) from date of injury, waiting time for MRI screening and time to medical assessment board (MAB).

RESULTS

Patients in the MORE Program had significantly shorter duration for RTW (MORE: 6.1 months,

CONTROL

12.8 months, p< 0.01), and more RTW cases (n= 64, 46.0%) compared to CONTROL group (n= 29, 27.4%). The MORE group also had much shorter waiting time for MRI scans (91.85 vs. 309.2 days, p< 0.001) and MAB referral after MRI scans (97.2 vs. 178.9 days, p= 0.001) compared to CONTROL group.

CONCLUSIONS

The MORE Program which emphasizes early intervention and early MRI screening, is shown to be effective in shortening sick leave and improving RTW outcomes of injured workers.

Limb Idleness Index (LII): a novel measurement of pain in a rat model of osteoarthritis

OBJECTIVES

Mechanical allodynia during ambulation in osteoarthritis (OA) animal models can be assessed as decreased extent of loading or decreased duration of loading. We propose to measure gait adaptation to pain by both mechanisms with the development of Limb Idleness Index (LII) in a rat model of knee OA.

METHODS

Rats were assigned to anterior cruciate ligament transection (ACLT), Sham, or Normal group (n = 6). Gait data were collected at pre-injury, 1, 2, 3 and 6 months post-injury. Ratios of target print intensity, anchor print intensity, and swing duration were combined to obtain LII. The association of gait changes with pain was assessed by buprenorphine treatment at 3 and 6 months post-injury. At 6 months, OA-related structural changes in knee joints were examined by μCT and results from histological scoring were correlated with LII.

RESULTS

As compared to pre-injury level (range 0.75-1.20), LII in ACLT group was increased at 6 months post-injury, which was significantly higher than that in Sham and Normal groups (P = 0.024). The increase in LII in ACLT group was effectively reversed by buprenorphine treatment (P = 0.004). ACLT group exhibited a significantly higher maximum Osteoarthritis Research Society International (OARSI) score as compared to Sham (P = 0.005) and Normal (P = 0.006) groups. Significant correlation was found between LII and side-to-side difference in OARSI score (r = 0.893, P < 0.001).

CONCLUSIONS

LII presents a good measurement for OA-related knee pain in rat model.

Reconstruction of hypoplastic thumb using hemi-longitudinal metatarsal transfer

The treatment of hypoplastic thumb (modified Blauth's type IIIb and IV) by pollicization is culturally unfavourable in the Chinese population and digit preservation is preferred. An innovative reconstruction method using a nonvascularized hemi-longitudinal metatarsal graft was performed in six cases with an average follow-up of 87.7 months. Overall hand function was good, as assessed using the Jebsen hand function test. Grip strength and pinch power were significantly weaker than the normal contralateral hand. There was no neurovascular or wound complication. The only donor site complication was a metatarsal fracture, which healed uneventfully with casting. There had been no permanent morbidity to the donor site, as all donor metatarsals hypertrophied and regained normal growth potentials. Linear growth of the transferred metatarsals was evident radiologically (average 1.5 mm/year). Free hemi-longitudinal metatarsal transfer is a feasible method with good functional outcome in the attainment of a 5-digit hand in patients with type IIIb/IV hypoplastic thumb.

IS SYMPTOMATOLOGY USEFUL IN DISTINGUISHING BETWEEN CARPAL TUNNEL SYNDROME AND CERVICAL SPONDYLOSIS?

Hand paraesthesia is a common symptom found in patients either with carpal tunnel syndrome or cervical spondylosis. To differentiate between the two conditions, it is important to identify additional diagnostic symptoms. Ninety-two patients with operated carpal tunnel syndrome and 138 patients with spinal surgery for cervical spondylosis were reviewed. After exclusion of cases co-morbid with both cervical spondylosis and carpal tunnel syndrome or other neurological disorders, 44 patients with carpal tunnel syndrome and 41 patients with cervical spondylosis were compared. There were significant differences in the symptomatology between the two groups. In carpal tunnel syndrome, 84% had nocturnal paraesthesia, 82% hand paraesthesia were aggravated by hand activity, and hand pain occurred in 64%. The incidences were only 10%, 7% and 10%, respectively in cervical spondylosis. Neck pain was present in 76% of cervical spondylosis but only in 14% of carpal tunnel syndrome, and lower limb symptoms were present in 44% of cervical spondylosis and only 9% in carpal tunnel syndrome.

TENOSYNOVIAL OSTEOCHONDROMATOSIS OF BOTH FLEXOR AND EXTENSOR TENDONS

An unusual case of a 52-year-old woman with tenosynovial osteochondromatosis involving both of the wrist flexor and extensor tendons is reported.

SUICIDAL MERCURY INJECTION INTO THE UPPER LIMB: A CASE STUDY

We report a rare case of self-injection of mercury into the subcutaneous tissue of the upper limb. A multi-disciplinary management approach was adopted including cooperation between toxicologists, orthopaedic surgeons, radiologists and environment safety personnel. Surgical removal of mercury under radiological screening and systemic intoxication treated by chelating agents, namely dimercaprol and succimer. Serial serum and urine mercury levels showed an initial rise despite surgical removal and returned to normal after a prolonged period of time. Safety precautions were taken during surgery to avoid inadvertent intoxication of staff. Contamination of the operation theatre was monitored by the amount of mercury vapour released into the air. All personnels involved in the management of the patient did not show any evidence of mercury intoxication.

ULTRASOUND FOR THE DETECTION OF VEGETATIVE FOREIGN BODY IN HAND — A CASE REPORT

Foreign bodies in soft tissues are commonly encountered in daily orthopaedic practice. While most of the metals and glass foreign bodies can be detected by plain radiograph, organic substances such as wood and vegetative materials are radiolucent. Unfortunately, these radiolucent foreign bodies are usually more prone to cause an inflammatory reaction and infection. The detection can be even more difficult in cases of multiple foreign bodies and in penetrating injuries with small innocuous skin wounds. Ultrasonography is a sensitive and reliable investigation for detection of foreign bodies in soft tissue. We present a case of penetration injury to thumb with residual radiolucent foreign bodies and demonstrate the proper role of ultrasonography in the management of foreign bodies in soft tissues.

Impaired bone healing in rabbits with steroid-induced osteonecrosis

Corticosteroids are prescribed for the treatment of many medical conditions and their adverse effects on bone, including steroid-associated osteoporosis and osteonecrosis, are well documented. Core decompression is performed to treat osteonecrosis, but the results are variable. As steroids may affect bone turnover, this study was designed to investigate bone healing within a bone tunnel after core decompression in an experimental model of steroid-associated osteonecrosis. A total of five 28-week-old New Zealand rabbits were used to establish a model of steroid-induced osteonecrosis and another five rabbits served as controls. Two weeks after the induction of osteonecrosis, core decompression was performed by creating a bone tunnel 3 mm in diameter in both distal femora of each rabbit in both the experimental osteonecrosis and control groups. An in vivo micro-CT scanner was used to monitor healing within the bone tunnel at four, eight and 12 weeks postoperatively. At week 12, the animals were killed for histological and biomechanical analysis.

In the osteonecrosis group all measurements of bone healing and maturation were lower compared with the control group. Impaired osteogenesis and remodelling within the bone tunnel was demonstrated in the steroid-induced osteonecrosis, accompanied by inferior mechanical properties of the bone.

We have confirmed impaired bone healing in a model of bone defects in rabbits with pulsed administration of corticosteroids. This finding may be important in the development of strategies for treatment to improve the prognosis of fracture healing or the repair of bone defects in patients receiving steroid treatment.

Digital gangrene following a green pit viper bite

In Hong Kong, the white-lipped green pit viper (Trimeresurus albolabris) accounts for the majority of venomous snake bites. In these patients, the cardinal features are local pain and swelling and mild coagulation abnormalities, but digital gangrene is uncommon. A 58-year-old woman was bitten on the left middle finger pulp by a white-lipped green pit viper. She developed local pain and swelling and coagulopathy, complicated by pulp tissue necrosis and digital gangrene of left middle finger. She fully recovered after amputation of the left middle finger at the mid portion.

Incorporating ultrasound-measured musculotendon parameters to subject-specific EMG-driven model to simulate voluntary elbow flexion for persons after stroke

BACKGROUND

This study was to extend previous neuromusculoskeletal modeling efforts through combining the in vivo ultrasound-measured musculotendon parameters on persons after stroke.

METHOD

A subject-specific neuromusculoskeletal model of the elbow was developed to predict the individual muscle force during dynamic movement and then validated by joint trajectory. The model combined a geometrical model and a Hill-type musculotendon model, and used subject-specific musculotendon parameters as inputs. EMG signals and joint angle were recorded from healthy control subjects (n=4) and persons after stroke (n=4) during voluntary elbow flexion in a vertical plane. Ultrasonography was employed to measure the muscle optimal length and pennation angle of each prime elbow flexor (biceps brachii, brachialis, brachioradialis) and extensor (three heads of triceps brachii). Maximum isometric muscle stresses of the flexor and extensor muscle group were calibrated by minimizing the root mean square difference between the predicted and measured maximum isometric torque-angle curves. These parameters were then inputted into the neuromusculoskeletal model to predict the individual muscle force using the input of EMG signals directly without any trajectory fitting procedure involved.

FINDINGS

The results showed that the prediction of voluntary flexion in the hemiparetic group using subject-specific parameters data was better than that using cadaveric data extracted from the literature.

INTERPRETATION

The results demonstrated the feasibility of using EMG-driven neuromusculoskeletal modeling with direct ultrasound measurement for the prediction of voluntary elbow movement for both subjects without impairment and persons after stroke.

Needle aponeurotomy for Dupuytren's contracture

PURPOSE

To review the efficacy and safety of needle aponeurotomy for Dupuytren's contracture in Chinese patients.

METHODS

Seven men and one woman aged 50 to 80 (mean, 67) years underwent needle aponeurotomy for Dupuytren's contracture. Five were manual workers and the other 3 were retired. Their chief complaints were difficulty moving the fingers, clumsiness of the hand, and occasional pain in the palm. No patient had any family history of Dupuytren's contracture.

RESULTS

41 points were released in 13 fingers (3 middle, 3 ring, and 7 little). Immediately after release, the respective mean flexion contracture correction of the metacarpophalangeal and proximal interphalangeal joints were 50 (from 50 to 0) and 35 (from 46 to 11) degrees. At 22-month follow-up, the respective mean residual flexion contracture of both joints were 12 and 27 degrees; the corresponding long-term improvements were 70 and 41%. No patient had a wound complication or neurovascular injury. All had a normal score for Disabilities of the Arm, Shoulder, and Hand.

CONCLUSION

For Chinese patients with Dupuytren's contracture, needle aponeurotomy is safe and effective. Long-term correction is better maintained in metacarpophalangeal than proximal interphalangeal joints (70 vs 41%).

[Arthroscopic volar wrist ganglionectomy]

As an original technique developed by our department, the preliminary result of arthroscopic resection of volar wrist ganglion was first published in 2003. Since then, there were few reports in the literature concerning this new treatment method. The aim of the study is to evaluate the long-term outcome of this treatment technique. From August 1997 to April 2005, 21 volar wrist ganglia with average size of 2 cm (range 1-4 cm) were treated. The average age of patients was 48.6 (range 18-63). Thirteen ganglia had previous treatment including either aspiration or open excision. Seventy-one percent of the operations were performed under local anesthesia. Wrist arthrogram was performed in 9 cases. Seven cases showed origin from radiocarpal joint and all proceeded to arthroscopic resection successfully. Arthroscopically, 75% of ganglia arose from the interval between radioscaphocapitate and long radiolunate ligament, and 25% from the interval between long radiolunate and short radiolunate ligament. Sixteen of the 21 ganglia could be excised by arthroscopic technique. The average follow up was 56 months (range 9-101 months). There were 2 recurrences. One was treated with repeated arthroscopic excision and the other by open excision. There was no impairment of wrist motion and function in all patients. No neurovascular complication was encountered. Arthroscopic resection was an effective treatment method for well-selected volar wrist ganglion arising from the radiocarpal joint in long run.

Firing properties of motor units during fatigue in subjects after stroke

The purpose of this work was to investigate the electromyographic (EMG) fatigue representations in muscles of subjects after stroke at the level of motor unit, based on the analysis of mean power frequency (MPF) in the power density spectrum (PDS) for intramuscular EMG and our previous modeling and experiment studies on the neuromuscular transmission failure (NTF). NTF due to the local muscular fatigue had been captured in motor unit signals from healthy subjects during a submaximal fatigue contraction previously. In this study, the EMG signals for the biceps brachii muscles were collected by needle electrodes from the affected and unaffected arms of six hemiplegic subjects after stroke, and from the dominated arm of six healthy subjects during a full maximum voluntary contraction (MVC) and a subsequent 20% MVC. The MPF of EMG trials detected intramuscularly during the full and 20% MVCs, and the parameters of motor unit action potential trains (MUAPTs) during 20% MVC were analyzed in three groups: the normal (from healthy subjects), unaffected (from subjects after stroke), and affected (from subjects after stroke). It was found that during the full MVC the MPFs of the normal and unaffected groups decreased more than the affected when monitored by a moving time window of 2 s. The comparison on the overall MPF during the full MVC for these three groups over the whole time course of the EMG signal (18 s) were: the affected overall MPF was higher than the unaffected (P < 0.05); and the unaffected overall MPF was larger than the normal (P < 0.05). However, no significant decrease in MPF was found for these three groups during 20% MVC. The NTF was captured in most MUAPTs in the groups of the normal and unaffected rather than in the affected group, symbolized by the lowered rates of change (RCs) of firing rate (FR) (P < 0.05), more MUAPTs with positive RCs of maximum oscillation (MO) in MUAPT power density spectra (P < 0.05), and the significant higher RCs of minimum inter-pulse interval (MINI) (P < 0.05) in the normal and unaffected compared to the affected group. Enhanced neural drives to the motor units of the unaffected and affected groups were observed during 20% MVC, which possibly came from the bilateral neural inputs due to the disinhibition of the ipsilateral projections in subjects after stroke. For identifying the fatigue associated with NTF, the motor unit firing parameters, FR, MINI, and MO, were more sensitive than the MPF. The results obtained in this work provided a further understanding on the EMG of the fatigue processes in paretic and non-paretic muscles during voluntary contractions.

Active mobilisation after flexor tendon repair: comparison of results following injuries in zone 2 and other zones

PURPOSE

To prospectively study the role of active mobilisation after flexor tendon repair.

METHODS

The standard modified Kessler's technique was used to repair 46 digits in 32 patients with flexor tendon injuries. Early active mobilisation of the repaired digit was commenced on the third postoperative day. Range of movement was monitored and recovery from injury in zone 2 was compared with injury in other zones.

RESULTS

There were 24 and 22 injuries in zone 2 and other zones respectively. The total active motion score of the American Society for Surgery of the Hand was measured. Patients with zone-2 injuries achieved similar results to those with other-zone injuries apart from a 3-week delay in recovery. The final results were good to excellent in 71% and 77% of zone-2 and other-zone cases respectively (p < 0.05). There were 2 ruptures in zone-2 and one rupture in zone-3 repairs (6.5%).

CONCLUSION

Preliminary results of this study showed that active mobilisation following flexor tendon repair provides comparable clinical results and is as safe as conventional mobilisation programmes although recovery in patients with zone-2 injury was delayed.

Oscillations in the power spectra of motor unit signals caused by refractoriness variations

The refractory period of a motor unit is an important mechanism that regulates the motor unit firing, and its variation has been found in many physiological cases. In this study, a new observation that an increase in the motor unit refractoriness results in an enhancement of oscillations, or ripple effects, in the motor unit output power density spectra (PDS) has been identified and studied. The effects of the refractoriness variation on the PDS of motor unit firing were investigated on three levels: theoretical modeling, simulation and electromyographic (EMG) experimentation on human subjects. Both theoretical modeling and simulation showed the enhanced oscillations, ripple effects, in MUAPT PDS, given the increase in the refractoriness. It was also found that the extent of the increment in output PDS oscillation could be related to the motor unit size and the mean firing rate of the stimulation. A needle EMG experiment on biceps brachii muscles of five healthy human subjects was carried out during isometric contraction at 20% maximum voluntary contraction (MVC) for 20 s with a fatigue effort proceeded by MVC. The increased oscillations in the PDS of the real MUAPTs were observed with the rising of the motor unit refractoriness due to fatigue. The study gives new information for EMG spectra interpretation, and also provides a potential method for accessing neuromuscular transmission failure (NTF) due to fatigue during voluntary contraction.

Long-term outcome of carpal tunnel syndrome after conservative treatment

The purpose of this study was to investigate the long-term prognosis of patients with carpal tunnel syndrome (CTS). We prospectively followed-up patients with CTS for 80 weeks. Thirty cases had been treated with a single injection of methylprednisolone acetate and another 30 with a 10-day course of prednisolone. At the end of the follow-up period, there were no significant differences in symptoms as measured by global symptom score and in the proportion of patients who progressed to decompressive surgery. Few patients who were not operated on (11.4%) remain asymptomatic.

Carpal tunnel release. A prospective, randomised study of endoscopic versus limited-open methods

Endoscopic carpal tunnel release has the advantage over open release of reduced tissue trauma and postoperative morbidity. Limited open carpal tunnel release has also been shown to have comparable results, but is easier to perform and is safer. We have compared the results of both techniques in a prospective, randomised trial. Thirty patients with bilateral carpal tunnel syndrome had simultaneous bilateral release. The technique of release was randomly allocated to either two-portal endoscopic release (ECTR) or limited open release using the Strickland instrumentation (LOCTR). The results showed that the outcome was similar at follow-up of one year using both techniques. However, the LOCTR group had significantly less tenderness of the scar at the second and fourth postoperative week (p < 0.01). There was also less thenar and hypothenar (pillar) pain after LOCTR. Subjective evaluation showed a preference for LOCTR.

Enhanced localization of osteoid osteoma with radiolabeling and intraoperative gamma counter guidance: a case report

Osteoid osteoma is a benign bone tumor that can be removed by marginal excision. Excessive removal of reactive bone may result in significant morbidity. We made use of the highly specific radioactive technetium uptake characteristic of osteoid osteoma for its localization. Radioactive technetium (25 mCi) was injected intravenously 2 hours before surgery to a 21-year-old male patient with an osteoid osteoma over the left distal radius. Tumor tissue was localized intraoperatively by a portable hand-held radioactive gamma counter to detect a focal high intensity of radioactivity. Complete tumor removal was shown by reduction of radioactivity to background level. This was confirmed by bone scintigraphy of the specimen and the forearm immediately after surgery. The defect was packed with cancellous bone graft taken from the ipsilateral distal radius through the same wound. Postoperative recovery was very satisfactory. We found this approach useful in limiting resection margin and surgical site morbidity in resection of osteoid osteoma.

Effects of antioxidants on pyridinoline cross-link formation in culture supernatants of fibroblasts from normal skin and hypertrophic scars

Free radicals are normally generated in many metabolic pathways. They are closely associated with inflammatory diseases. The aim of this study was to investigate the effects of free radicals and their antioxidants on the formation of pyridinoline using human fibroblasts from normal skin and hypertrophic scars. The significance of the increase in pyridinoline cross-links is that large quantities have been found in hypertrophic scars formed post-burn than in normal skin, and that catalase was effective in reducing the pyridinoline cross-link formation in hypertrophic scars. The pyridinoline cross-link concentration expressed in nM/ micro g hydroxyl proline was found to be higher in the culture supernatants of the fibroblasts from hypertrophic scars (9.04 +/- 2.74) than that of normal skin (7.55 +/- 2.1). When the human fibroblasts from normal skin and hypertrophic scar were subject to hydroxyl radicals generated by the Fenton reaction, there was no significant increase in pyridinoline cross-link concentration (nm/ micro g hydroxyl proline) in the supernatants compared with the control. When the controls plus various treatments with free radicals were subject to different antioxidants, including superoxide dismutase, catalase, glutathione peroxidase, and desferrioxamine, it was found that catalase alone was most effective in scavenging hydroxyl radicals as determined by the decrease in pyridinoline cross-links.

Reconstruction of shoulder function using a reflected long head biceps: a moment arm study

A tendon transfer technique is proposed for the reconstruction of the paralyzed shoulders secondary to brachial plexus injury. This innovative technique does not require bone-to-bone or tendon to-bone fixation, and attempts to overcome other clinical limitations such as those due to insufficient length of donor muscle. The approach is referred to as the reflected long head biceps (RLHB) technique. The long head of biceps tendons is utilized as a bridging tendon graft. Two surgical alternatives, namely the through-deltoid (TD) pathway and the sub-deltoid (SD) pathway, were studied. The moment arms of the transferred tendons were assessed and reported. The TD technique yielded a larger moment than the SD technique. In the plane 30 degrees anterior to the scapular plane, the average moment arms were 3.8cm TD and 3.0cm SD at zero elevation. Such differences tended to further widen with increasing elevation. At 80 degrees elevation, the moment arms became 3.2cm TD and 1.2cm SD. The results supported the clinical feasibility of this RLHB tendon transfer approach.

In vivo determination of subject-specific musculotendon parameters: applications to the prime elbow flexors in normal and hemiparetic subjects

OBJECTIVE

This study aimed at estimating the musculotendon parameters of the prime elbow flexors in vivo for both normal and hemiparetic subjects.

DESIGN

A neuromusculoskeletal model of the elbow joint was developed incorporating detailed musculotendon modeling and geometrical modeling.

BACKGROUND

Neuromusculoskeletal modeling is a valuable tool in orthopedic biomechanics and motor control research. However, its reliability depends on reasonable estimation of the musculotendon parameters. Parameter estimation is one of the most challenging aspects of neuromusculoskeletal modeling.

METHODS

Five normal and five hemiparetic subjects performed maximum isometric voluntary flexion at nine elbow positions (0 degrees -120 degrees of flexion with an increment of 15 degrees ). Maximum flexion torques were measured at each position. Computational optimization was used to search for the musculotendon parameters of four prime elbow flexors by minimizing the root mean square difference between the predicted and the experimentally measured torque-angle curves.

RESULTS

The normal group seemed to have larger maximum muscle stress values as compared to the hemiparetic group. Although the functional ranges of each selected muscle were different, they were all located at the ascending limb of the force-length relationship. The muscle optimal lengths and tendon slack lengths found in this study were comparable to other cadaver studies reported in the literature.

CONCLUSION

Subject-specific musculotendon parameters could be properly estimated in vivo.

RELEVANCE

Estimation of subject-specific musculotendon parameters for both normal and hemiparetic subjects would help clinicians better understand some of the effects of this pathological condition on the musculoskeletal system.

Applied anatomy of the axillary nerve for selective neurotization of the deltoid muscle

Morphologic and internal topographic features of the axillary nerve were studied in 40 cadaveric shoulders to provide anatomic data for selective neurotization of the deltoid muscle in axillary nerve injury. The axillary nerve can be divided into three segments. Proximal to the subscapularis muscle, the axillary nerve is a single nerve trunk. Nerve fascicles to the deltoid muscle are identified at its lateral part. In front of the subscapularis muscle, the axillary nerve forms into the lateral and medial fasciculi groups. Distal to the subscapularis muscle, the nerve divides into anterior and posterior branches, which are continuations of the lateral and medial fasciculi groups, respectively. The anterior branch contains all fibers that innervate to the anterior and middle deltoid muscle. In 90% of cases, the posterior branch contains part or all nerve fibers to the posterior deltoid muscle. Nerve fibers to the teres minor and cutaneous sensory fibers are found in the posterior branch. In neurotization of the deltoid muscle, the best approach is to match the donor nerve to the lateral fasciculi group, which will give the highest percentage of reinnervation of the deltoid muscle.

Uncommon hand tumours

This paper presented clinical examples of some rare or uncommon presentations of tumours of the hand, including glomus tumour, intraosseous dermoid, fibrolipoma of the radial nerve, blastomycotic cyst and synovial sarcoma. Each lesion is illustrated by review of case histories, radiological and pathological features.

Current treatment of ganglion of the wrist

Ganglion of the wrist is one of the the most common lesions of the hand. The cause of pain in an occult dorsal wrist ganglion has been linked to compression of the posterior interosseous nerve at the wrist. A case is presented in this paper and the pathoanatomy discussed. Ultrasound-guided aspiration after hyaluronidase instillation provided a useful alternative to surgery with a high success rate. Arthroscopic decompression for dorsal and palmar wrist ganglia offered the patient the benefit of smaller surgical scars and a high success rate. A description of the surgical techniques, pathoanatomy, and early results of the authors and a review of the literature is presented.

Local vs systemic corticosteroids in the treatment of carpal tunnel syndrome

The authors compared the effectiveness of low-dose, short-term oral prednisolone vs local methylprednisolone injection in a prospective, double-blinded, parallel treatment study of carpal tunnel syndrome (CTS). A single injection of 15 mg methylprednisolone resulted in significant improvement in global symptom scores over a 12-week period. This study demonstrated the superiority of local steroid injection to oral steroid in the treatment of CTS.

Stability of reconstructed paralyzed shoulders using a reflected long head biceps technique

A new tendon transfer technique is proposed for the reconstruction of the paralyzed shoulders secondary to Brachial Plexus Injury (BPI). In this tendon transfer, the long head of the biceps tendons is utilized as a bridging tendon graft. It is reflected at the exit of the bicipital groove, passed through the deltoid and directed to the trapezius. The technique is referred to here as the Reflected Long Head Bicepts (RLHB) technique. This study evaluated the effect of this tendon transfer on the anterior, posterior, and inferior stability of the reconstructed should using cadaveric specimens. It was shown that loading of the RLHB contributed significantly to anterior stability of the reconstructed shoulder for 90 deg elevation in the scapula plane. The mean displacement was reduced by 56 percent with RLHB loaded (p<0.01), by 56 percent with the rotator cuff loaded (p <0.005), and by 67 percent with both the RLHB and the rotator cuff loaded (p<0.004). For the post-operation conditions, variation of the directions of RLHB had no significant effect on joint displacement in response to anterior loading. The RLHB tendon also contributed to the posterior and inferior stability for the low and middle elevations in the plane of scapula. Two variations of the RLHB tendon transfer procedures, namely the "Sub-Deltoid" and the "Through-Deltoid" techniques, were introduced and studied. These two techniques did not seem to have significantly different effects on the displacement of the humeral head in response to both posterior and inferior loading. The results of this study seemed to support the clinical feasibility of this tendon transfer approach as far as the biomedical stability of the reconstruction is concerned.

Sonography of the normal scapholunate ligament and scapholunate joint space

PURPOSE

The aims of this study were to assess the visibility of the normal scapholunate ligament on sonography and to establish the normal scapholunate joint space width in the neutral position and radial and ulnar deviation.

METHODS

Two hundred normal wrists in 100 subjects (55 men and 45 women; mean age, 40 years; range, 19-83 years) were examined with high-resolution sonography (5-12-MHz linear-array transducer). The visibility and thickness of the scapholunate ligament were recorded. The width of the scapholunate joint space, or interval, was measured in the neutral position and radial and ulnar deviation. The width of the distal radius was recorded as a comparative standard for the patients' body habitus.

RESULTS

The dorsal scapholunate ligament was completely (100%) visible in 95 wrists (48%), partially (> or = 50%) visible in 60 (30%), barely (< 50%) visible in 15 (8%), and not visible in 30 (15%). The volar scapholunate ligament was completely visible in 13 wrists (7%), partially visible in 17 (9%), barely visible in 15 (8%), and not visible in 151 (76%). The proximal component of the ligament was not visible in any subject. Measurement of the scapholunate interval was limited by the lack of identifiable anatomic marks for reference. The mean width of the dorsal scapholunate interval was 4.2 mm (range, 2.3-6.3 mm) in the neutral position. The interval did not differ more than 2.5 mm between the left and right wrists. No predictable change in width on ulnar or radial deviation was evident. The mean scapholunate intervals and mean distal radial width were significantly wider in men than in women and on the right side than on the left side.

CONCLUSIONS

The dorsal scapholunate ligament is completely or partially visible in 78% of normal wrists. Its detection following injury may help to exclude the possibility of scapholunate dissociation. There is a quite wide variation in scapholunate interval widths on sonography and an unpredictable response with stress testing. The absence of a visible scapholunate ligament on sonography does not indicate injury.

Removal of the lateral or medial third of patellar tendon alters the patellofemoral contact pressure and area: an in vitro experimental study in dogs

OBJECTIVES

To compare patellofemoral contact pressure and areas after immediate removal of the lateral, central, or medial third of patellar tendon.

DESIGN

In vitro experiment in 12 dogs.

BACKGROUND

Alteration of the vector sum of the quadriceps muscle contraction after removal of partial patellar tendon might result in changes of patellar tracking in the trochlea.

METHODS

Patellofemoral contact pressure and areas were recorded using Fuji pressure-sensitive film at 45 degrees, 60 degrees, and 90 degrees of knee flexion under an isometric quadriceps force of 100% body weight. The patellofemoral contact imprint from the intact knees were obtained as control, and the lateral (n=4), central (n=4), and medial (n=4) third of the patellar tendon were subsequently removed and the patellofemoral contact imprint was recorded.

RESULTS

The patellofemoral contact area was found to increase with increasing knee flexion angles. No change in patellofemoral contact pressure and areas was found after removal of the central third patellar tendon. However, after removal of either lateral or medial third of patellar tendon, the patellofemoral contact was rotated with increasing knee flexion angles. This was due to the altered vector sum of the quadriceps force, resulting in significantly decreased patellofemoral contact areas and simultaneously a significantly increased contact pressure, characterized with concentration of patellofemoral contact pressure on both lateral and medial facets of the patellofemoral joint.

CONCLUSIONS

The results suggest that removal of the central third of patellar tendon may not alter the patellofemoral contact pressure and areas as compared with removal of either lateral or medial third of patellar tendon that may result in an altered postoperative tracking mechanism of the patellofemoral joint immediately after operation.

RELEVANCE

Findings of this in vitro animal study supports the use of central third of patellar tendon as autograft for anterior cruciate ligament reconstruction. However, further experimental studies are needed to investigate how the postoperative healing of the host patellar tendon will influence the findings obtained from this in vitro study.

Alteration of patellofemoral contact during healing of canine patellar tendon after removal of its central third

Alterations of the patellofemoral (PF) contact pressure and area were assessed using pressure-sensitive film after the removal of the central third of patellar tendon (PT) with healing over time in twelve dogs. The contralateral knee served as control. Histological sections were prepared for descriptive evaluation. No alterations in PT strain, PF contact pressure and area were measured immediately after the removal of the central third of PT compared with that before its removal. Compared with contralateral control, the healing of the donor PF induced a significantly increased PF contact area but not PF contact pressure in the specimens harvested at 6, 12, and 18 months after operation. Increased PF contact area indicated a proximal shift of the PF joint contact during flexion, which was associated with an increased strain of the healing PT under loading. The healing PT became hypertrophic compared with control, but the differences in the cross-sectional area were reduced over time. Histologically, a poorly organized extracellular matrix was observed at 6 months, with a progressive improvement in collagen fiber alignment up to 18 months postoperatively. The results of this study suggest that the removal of the central third of PT does not immediately change PF contact pressure and areas. However, remodeling of the healing tendon may cause an elongated PT, resulting in an increase in PF contact area under a given quadriceps force by knee extension.

Free posterior tibial perforator flap: anatomy and a report of 6 cases

Anatomy of cutaneous perforators of the posterior tibial artery were studied in 20 limbs of 10 cadavers. The majority of the perforators (n = 74, 61%) were located in the middle two quarters of the leg, at an average of 18.6 cm (s.d. 4.5 cm; range 10.5-26 cm) from the medial malleolus, or around 54% (s.d 16%) of the length of the leg. There were usually 3 or 4 perforators in this region, with an average caliber of 1.5 mm (s.d. 0.2 mm; range 1-2 m.m.) and an average length from the posterior tibial artery to the skin of 4.0 cm (s.d. 1.3 cm; range 2.5-6 c.m.). A free fasciocutaneous skin flap based on one of these perforators (the posterior tibial perforator flap, PTP flap) was successfully transplanted in 6 cases. This modified technique of the posterior tibial flap enables the surgeon to retain the posterior tibial artery when the skin of the medial aspect of the leg is chosen to be used as skin flap donor.

A histomorphometric observation of flows in cortical bone under dynamic loading

Ferritin was used as a histological marker for interstitial fluid flows in four goats. Two transcortical pins were inserted into each tibia mediolaterally-one at the proximal side and one at the distal side of the diaphysis. For the experimental limb, dynamic loading was applied to the pins on the lateral side. The contralateral limb was used as control. Ferritin was injected into the nutrient arteries feeding the two tibiae. The goat was then euthanized immediately. Undecalcified slides of the tibial cortical bone from both the experimental and the control limbs were studied histologically. Percentages of Haversian systems marked with ferritin halos and the average radial distance of ferritin transudation away from the Haversian canals were assessed. Results for the medial and lateral sides of both the experimental and control tibiae were reported. Significant differences in the ferritin transudation distance were found between the experimental and the control tibia (P < 0.005) and between the medial and the lateral sectors (P < 0.05). The approach documented in this paper could be used to address systematically how external loading might affect the transport phenomena in cortical bone.

Impairment of hand function and loss of earning capacity after occupational hand injury: prospective cohort study

OBJECTIVE: To examine the loss of earning capacity and permanent impairment of a cohort of male patients who had experienced finger amputation due to occupational injury. DESIGN: Prospective cohort study. SETTING: University teaching hospital, Hong Kong. PATIENTS: Twenty-eight male patients aged 26 to 55 years who presented with work-related finger amputations in their dominant right hand from 1990 through 1991. MAIN OUTCOME MEASURES: Type and extent of amputation, and hand function before and after (mean, 11 months; range, 8-6 months) the patients' return to work. Assessment results were compared with patients' percentage loss of earning capacity as calculated using the scale described in the Employees' Compensation Ordinance of Hong Kong. RESULTS: Patients with injuries that corresponded to a loss of earning capacity of 12% or greater had a significant impairment in their hand function (P<0.05); the hand function of this group after their return to work significantly improved (P<0.05). There were no significant differences between the loss of earning capacity scores as calculated by the Hong Kong, American Medical Association, or Indian Medical Association scales. CONCLUSION: Patients whose loss of earning capacity of 12% or greater are likely to have significant long-term impairments of hand function. Thus, a more intensive rehabilitation programme should be provided to this group.

Histomorphological study on pattern of fluid movement in cortical bone in goats

Streaming potential is considered one of the most important mechanisms to moderate the function of osteoblasts and osteocytes in bone growth, remodeling and fracture repair. The present study was designed to demonstrate the fluid flow pattern in the cortical bone matrix in an animal model using undecalcified histological techniques. Immediately after injection of ferritin into the tibia nutrient artery of four adult goats, the animals were euthanized. Undecalcified transverse and longitudinal blocks of cortical bone obtained from the tibial diaphysis were immersed in Perl's reagent and embedded in methyl methacrylate. Sections were cut and ground to 30-50 microm thickness for histomorphological evaluation at different magnifications and focusing levels. A serial grinding technique was used to validate the observations made at different focusing levels. As expected, ferritin was observed in the interstitial compartment in both transverse and longitudinal sections. In osteons sectioned transversely, the pattern of centrifugal movement of ferritin marker was demonstrated as single or multiple halos around the Haversian canal. The most apparent halo in osteons with multiple halos was the one found closest to the Haversian canal. The total number of identifiable single or multiple halos increased or was altered when counting was made with higher magnification or at different focusing levels, respectively. Irregular and incomplete ferritin halos indicated structural complexity of the osteons. Overall, the pattern of ferritin movement was consistent with bulk interstitial fluid flow influenced by both hydrostatic pressure and transudation. This study demonstrated for the first time multiple concentric halos of the fluid flow marker ferritin around Haversian canals in the cortical interstitial compartment. The results suggest that the undecalcified technique might be a useful method for qualitative and quantitative studies on cortical fluid flow.

Lengthening of a one-bone forearm. A sequel of neonatal osteomyelitis

An 8-year-old girl presented with marked shortening of the right forearm due to destruction of both the radius and ulna secondary to neonatal osteomyelitis. A one-bone forearm operation was performed to achieve a stable forearm. Two years later, the one-bone forearm was lengthened for 6 months by callus distraction (callotasis) achieving 12 cm of extra length. The patient was last followed up at the age of 16. The appearance and functional outcome of the right upper limb had been improved and she was independent in all activities of daily living.

A longitudinal study of C3, C3d and factor Ba in burn patients in Hong Kong Chinese

A longitudinal study of serum C3, C3d and fragment Ba was carried out in 53 burn patients of Chinese origin whose total burn surface area ranged from I to 45%. Complement C3 was found to be activated on or before day 7 post-burn. The sharp increase in C3d suggested an acute inflammatory response. In addition factor Ba was increased in these patients, suggesting that the alternative pathway was also activated following thermal injuries. The fluctuations of C3, C3d and Factor Ba observed about 1 year after injury suggested chronic inflammation associated with long term of outcome of healing in the burn sites.

Vascularized bone grafts in the treatment of juxta-articular giant-cell tumors of the bone

The clinical results of vascularized bone grafts in 39 patients with giant-cell tumor affecting the extremity were evaluated. The sites involved were the proximal tibia (8), proximal femur (4), calcaneus (1), proximal humerus (8), and distal radius (18). Osteoarticular replacement was performed in patients with giant-cell tumor involving the radius; in 15 of these, a suitably tailored vascularized iliac crest graft was used, and in the remaining three, the fibula was used. Follow-up ranged from 2 to 7 years, with an average of 3.3 years. Clinical results were judged on the basis of functional and radiologic evaluations. Reconstructions involving the distal radius were evaluated separately from the rest of the juxta-articular grafts. Excellent results in 17 and good results in three of the juxta-articular grafts were observed. Eighteen patients with the distal radius affected were followed-up for periods ranging from 2 to 12 years. Non-union was seen in one, carpal subluxation in five, and spontaneous radiocarpal fusion in one patient. A pain-free functional wrist was retained in 17 of these 18 patients. Three local recurrences were observed (2.5 percent). The vascularized bone graft provided a good biological and mechanical support to the subchondral bone and overlying articular cartilage. Satisfactory reconstruction was thus possible following wide resection, without sacrificing joint function and with gratifying oncologic results. The use of a suitably tailored block of vascularized iliac crest is an acceptable method to preserve wrist and radio-ulnar joint motion, following excision of the distal radius affected by a giant-cell neoplasm.

Bridging nerve defects with differently treated muscle grafts: assessment of microsphere technique for measurement of blood flow in rats

OBJECTIVE

To select advanced points from differently treated muscle grafts and explore a new conduit to bridge nerve defects.

METHODS

A total of 70 Sprague-Dawley rats were employed in this experiment. We applied a frozen probe to freeze the muscle in situ to disrupt any cellular elements of the local muscle grafts, but blood vessels to the muscle were carefully preserved. Radioactive microsphere technique was employed to visualize the blood supply to the muscle grafts. Immunohistochemical staining and ultrastructural observation were also carried out to assess the results of nerve regeneration.

RESULTS

The in-situ frozen muscle grafts were revascularized within the first 3 days, which led to fast migration of macrophages and Schwann cells. That was really reflected in the final results: the early incursion of regenerating axons, more regenerating axons at the early stage both in the grafts and distal stumps, and thicker myelin sheath of regenerating axons.

CONCLUSIONS

The in-situ frozen autogenous muscle graft is useful in the repair of sciatic nerve of rats. In the thicker and longer grafts the benefits will be more remarkable. It will be the most useful technique for nerve repair, especially in the repair of a large nerve gap in a poor recipient bed.

Recent changes in the pattern of hand injuries in Hong Kong: a regional hospital survey

Adult inpatients with injuries to the hand admitted to the Department of Orthopaedics and Traumatology of the Prince of Wales Hospital, Hong Kong, from June 1992 to May 1993 were surveyed (n=533). The causes of injury, mechanisms involved, and the nature of injuries were recorded. The injuries were further graded according to four different scales. It was found that 65% of the injuries were sustained at work, 15% in domestic environments, 7.6% during sports or recreational activities, and 6.5% in traffic accidents. Injuries caused by heavy machinery amounted to 26.7% and the electric saw was the second most common cause of injury accounting for 9.4% of injuries. Crush injuries occurred in 37.8%. The incidence of hand injury is estimated to be 600 per 100,000 population annually. The pattern of hand injuries bears some similarities and differences to published series. A comparison with data obtained in Hong Kong in the 1970s shows that major changes have occurred. We need continual surveillance of hand injury patterns.

Delivery of medication by iontophoresis to treat post-burn hypertrophic scars: investigation of a new electronic technique

At present, direct current (DC) and pulsed direct current (PDC) methods are used for iontophoresis. Although the DC field has high efficiency, it exhibits some side-effects. The PDC field has little side-effects, but the efficiency is lower. In this study, a new iontophoretic drug device was designed for providing the maximal efficiency with the minimal side-effects. Tests of animal and human models showed that the permeation rate of the new field was higher than that of PDC and DC fields, and side-effects were lower than that of the DC field.

The cutometer and ultrasonography in the assessment of postburn hypertrophic scar--a preliminary study

Sixteen patients with various degrees of postburn hypertrophic scars were evaluated by ultrasonography and elastometry. An Aloka Echo Camera (SSD-500) with a 7.5 MHz probe and a Cutometer SEM 575 skin elastometer were used. Serial monthly examinations were performed using both pieces of equipment. In some patients, more than one scar was assessed. The assessments were correlated with clinical grading of the progress of the scars. It was noted that ultrasonography was very sensitive in the localization of scar tissues, distinguishing them from normal skin, assessment of thickness and also delineation of the extent of scar tissues. The subcutaneous part of the scar could be assessed. Cutometer SEM 575 is a new machine that applies a gentle suction to the skin to measure its viscoelasticity. It is sensitive, the inter-observer variation is low, and it could be used for the grading of a scar. These two assessment techniques compliment other methods of scar assessment and will prove useful when assessment of response to treatment is required.

Multiple chop wounds in Hong Kong. An epidemiological study of an unusual injury

Knife injuries can be classified into stabbing injuries and multiple laceration or multiple chops, the latter being much more common in Chinese communities. It is the mark of criminal gang attacks with their tendency to use long knives and choppers rather than guns. The intention is often to wound rather than kill. A survey of 89 cases revealed that 90% of the victims are men, with a mean age of 27 years; 75% was admitted to the hospital at night, and in 78% of the cases the assailants were persons unknown, or so we were told by the victims. The reasons for the attacks were also not given. Most of the women victims were assaulted by their spouse. Some 74% of the patients suffered three to six lacerations; 62% of the injuries were on the extensor surfaces of the upper limbs, while the hand and the back of the trunk were also common sites. The type of management differs from that for stabbing injuries. There were no fatalities, and less than half of the patients required blood transfusion. The average hospital stay was 6.2 days. The morbidity of these injuries involves damaged tendons and nerves.

Sequential flap transplantations for total reconstruction of avulsion amputation of the fingers--a case report

The degloved and partially amputated ring and middle fingers of the left hand of a 40-year-old male was re-surfaced with two flaps transplanted sequentially: the toe wrap-around flap and the reversed pedicled metacarpal flap. Sensate and non-glabous skin was restored to the tip of the finger stumps as well as a supple full thickness reconstruction of the web space was achieved.

Congenital pseudarthrosis of the ulna

Congenital ulnar pseudarthrosis is a very rare condition. Two cases are reported in addition to 36 already reported in the English literature. One of the cases reported had a "one-bone forearm" procedure done, with a satisfactory result after 6 years. The second case had a free vascularized fibula graft procedure with restoration of the bony alignment and union after 8 months of follow-up.

Congenital pseudarthrosis of the tibia in adults treated by a free vascularized iliac crest graft

Congenital pseudarthrosis of the tibia is a rare condition. It usually presents during early childhood, at which time the surgeon is faced with numerous challenges including difficulties in achieving union and preventing refractures and recurrences. Patients frequently end up with a severe deformity or an amputation. When an adult patient presents with previously untreated congenital pseudarthrosis of the tibia, the surgeon is faced with the additional problems of a long-standing soft tissue contracture and disuse atrophy of the limb. Two patients with congenital pseudarthrosis of the tibia were treated by free vascularized iliac crest graft. Soft tissue deformity was corrected using an external fixation device. The patients were not freely ambulatory before surgery. Union across the pseudarthrosis was achieved in both patients with a double-staged operation, within a short period of time. A functional stable painless limb with good knee and ankle motion has allowed both patients to resume bipedal gait and achieve a successful rehabilitation.