Treatment of mixtures of toluene and n-propanol vapours in a compost-woodchip-based biofilter.

The present work describes the biofiltration of mixture of n-propanol (as a model hydrophilic volatile organic compound (VOC)) and toluene (as a model hydrophobic VOC) in a biofilter packed with a compost-woodchip mixture. Initially, the biofilter was fed with toluene vapours at loadings up to 175 g m(-3) h(-1) and removal efficiencies of 70%-99% were observed. The biofilter performance when removing mixtures of toluene and n-propanol reached elimination capacities of up to 67g(toluene) m(-3) h(-1) and 85 g(n-propanol) m(-3) h(-1) with removal efficiencies of 70%-100% for toluene and essentially 100% for n-propanol. The presence of high n-propanol loading negatively affected the toluene removal; however, n-propanol removal was not affected by the presence of toluene and was effectively removed in the biofilter despite high toluene loadings. A model for toluene and n-propanol biofiltration could predict the cross-inhibition effect of n-propanol on toluene removal.

Abnormal ulnar nerve anatomy in the distal forearm pre-disposes to post-traumatic ulnar neuritis at the wrist.

Anatomical variations of the ulnar nerve have been described at the level of the elbow and in Guyon's canal, while the path in the forearm has always been assumed to be constant. We present a case of compressive ulnar neuropathy at the wrist pre-disposed by a presumed congenital variation of the path of the ulnar nerve at the level of the wrist which improved following surgical release of the constriction caused as a result of it.

Complex fracture-dislocation of the proximal interphalangeal joint of the hand. Results of a modified pins and rubbers traction system.

We reviewed 13 patients with a complex fracture-dislocation of the proximal interphalangeal joint of a finger and one patient with a complex fracture-dislocation of the interphalangeal joint of thumb. We had treated these injuries using a pins and rubbers traction system which had been modified to avoid friction of the pins against the bone during mobilisation of the joint in order to minimise the risk of osteolysis. A Michigan hand outcome questionnaire was used for subjective assessment. The active range of movement (AROM) of the proximal and distal interphalangeal joints and the grip strength were used for objective assessment. The mean follow-up was 34 months (12 to 49). The mean normalised Michigan hand outcome score was 84. The mean AROM of the proximal interphalangeal joint was 85 degrees and that of the distal interphalangeal joint 48 degrees. The mean grip strength was 92% of the uninvolved hand. Twelve patients have returned to their original occupations. There has been no radiological osteolysis or clinical osteomyelitis. This modified traction system has given acceptable results with a low rate of complications. It is light, cheap, effective and easy to apply.

Distal radioulnar joint incongruity after shortening of the ulna.

Coronal sections of the distal radioulnar joint (DRUJ) were studied in 13 preserved cadaveric wrists specimens before and after 2 mm of shortening of the ulna. The DRUJs were subclassified on the basis of the DRUJ angle and depth of the sigmoid notch. The changes in extent and location of area of contact and radioulnar separation were noted. Although reduction in area of contact occurred in every specimen and DRUJ type, the maximum radioulnar separation and reduction in area of contact occurred in the DRUJ type IB and IIB. This could be a possible factor producing point loading and subsequent occurrence of DRUJ remodelling in the long-term after shortening of the ulna.

Average versus maximum grip strength: which is more consistent?

The average of three consecutive measurements is the most frequently used method for grip strength assessment. The purpose of this study was to compare the consistency of the maximum value with that of the average value of three consecutive measurements of grip strength. One hundred healthy volunteers participated in this study. Three measurements of grip strength were taken on two occasions separated by 2 weeks. For each hand, two average values and two maximum values were obtained. Ninety-five per cent limits of agreement for the average method were - 8.3 (-23%) to +7.2 (+20%)kg and for the maximum method were - 8.8 (-23%) to + 8 (+21%)kg. Both methods of grip strength assessment were found to be highly consistent with no statistically significant difference.

The position of the centre of the distal radial articular surface in the sagittal plane: a radiological study.

Using a digital vernier calliper, measurements of the position of the centre of the distal radial articular surface in the sagittal plane with respect to the long axis of the distal radius were made on 50 lateral radiographs of normal wrists. In all 50 cases, the centre of the distal radial articular surface was palmar on the long axis of the radius. The mean value for this palmar position was 5.3mm (44% of the radial shaft width). There was no correlation between the position of the centre of the distal radial articular surface and either the width of the radial shaft, the length of the articular surface of the distal radius or the age or sex of the individuals. However, the position of the centre of rotation was found to correlate with palmar tilt. The palmar position of the centre of the distal radial articular surface on the long axis of the radius may be biomechanically important.

Palmar cortical angle of the distal radius: a radiological study.

Fifty lateral radiographs of normal wrists were viewed to determine the palmar cortical angle of the distal radius. The palmar cortical angle is different to its previously described palmar tilt or angulation. The mean value for the palmar cortical angle was 37 degrees (range, 26-50 degrees). This may be clinically important in the design of palmar plates for the distal radius.

Effect of wrist position on power grip and key pinch strength following carpal tunnel decompression.

Power grip and thumb key pinch strength were measured pre- and immediately postoperatively in 30 patients with carpal tunnel syndrome while the wrist was in flexion and extension. The carpal tunnel decompression was performed under local infiltration with 1% lignocaine. Grip strength decreased more in wrist flexion than in wrist extension. No difference was found in thumb pinch strength. The authors conclude that some of the immediate postoperative loss of grip strength in wrist flexion can be attributed to prolapse of flexor tendons out of the carpal tunnel in this position.

Blatt's capsulodesis for chronic scapholunate dissociation.

We have reviewed prospectively 44 cases of chronic scapholunate dissociation treated by Blatt's dorsal capsulodesis. The diagnosis was based on clinical and arthroscopic criteria. The minimum follow-up was 2 years. The results were analysed clinically and radiologically. Postoperatively statistically significant reductions in wrist movements and grip strengths were noted. Delay in surgery and presence of compensation claims were also statistically significant factors. Patients with a high column/row index had higher overall good and excellent results. The scapholunate gap, scapholunate angle, carpal height and the type of instability as diagnosed on arthroscopy and cineradiography did not affect the outcome significantly. The scapholunate gap, scapholunate angle and the carpal height did not change significantly after operation.

Distal volar radial plates: how anatomical are they?

BACKGROUND: Fractures of the distal radius are common, with volar locking plates being increasingly used in their treatment. They aim to provide stable internal fixation and are designed to mirror the natural anatomy. Current volar plate designs incorporate a volar cortical angle (VCA) of 25 degrees. HYPOTHESIS: The aim of this study is to determine whether the VCA in uninjured distal radii corresponds accurately with modern volar plate designs. MATERIALS AND METHODS: A retrospective radiological analysis utilizing Computed Tomography scans to assess the VCA of 100 distal radii. Each distal radius was subjected to 3 measurements of the VCA in the sagittal plane. RESULTS: One hundred patients were identified (67 male, 33 female; mean age 37.4 years). The mean VCA was 32.9 degrees (S.D.±5.14 degrees). The VCA in male patients was significantly greater than in females (33.6 vs 31.5 degrees; P=0.04). There was a statistically significant difference between the lateral VCA and medial VCA (32.2 vs 34.3 degrees, P=0.02). DISCUSSION: Our study clearly demonstrates that the VCA measured in the distal radius is significantly greater than the volar angulation incorporated within modern plate design. Given that the aim of ORIF is to anatomically reconstruct the distal radius, our study highlights that this may not be possible with current plates. LEVELS OF EVIDENCE: Level IV Retrospective case series.

Operative treatment improves patient function in recalcitrant medial epicondylitis.

The purpose of this retrospective study was to assess the outcome of open surgery for patients with recalcitrant medial epicondylitis following failed conservative management. The clinical results are presented for 15 patients (17 elbows) who were reviewed at a mean follow-up of 66 months. Operative treatment improved patient function significantly with a mean increase in grip strength of 10kg and a mean decrease (improvement) in DASH (Disabilities of the Arm, Shoulder and Hand) score of 25.7. All but one patient experienced little or no residual elbow discomfort and had excellent Mayo elbow performance scores postoperatively. Eleven of the twelve patients who were previously in employment were able to return to work within eight weeks of surgery. This study demonstrates that operative treatment for recalcitrant medial epicondylitis is effective in restoring patient function and strength.

Bone grafting in four-corner mid-carpal fusion.

Four-corner fusion is an accepted surgical treatment for established SLAC and SNAC wrist. We describe a technique of bone grafting to be used in conjunction with any of the standard fusion techniques. A step by step, illustrated approach allows the easy placement of an autograft which is in contact with all surfaces of the bones involved in the fusion.

Lead contamination of surgical gloves by contact with a lead hand.

Background. "Lead hands" are frequently used to maintain hand and finger position in hand surgery. The malleability and strength of lead make it ideal for this purpose. The aim of this study was to determine the amount of lead transferred to a surgeon's glove during handling of a lead hand. Method. Sterile surgical gloves were wiped over the surface of a lead hand. The number of wipes was varied, the gloves were then sent to a trace elements laboratory, and the lead content transferred to each glove was determined. Results. The amount of lead transferred to each glove increased with increasing exposure to the lead hand. After twenty wipes, up to 2 mg of lead was transferred to the surgeon's glove. Covering the lead hand with a sterile drape markedly reduced the lead transferred to the surgeon's glove. Conclusion. Significant amount of lead is transferred on to the gloves after handling a lead hand. This risks wound contamination and a foreign body reaction. Covering the lead hand with a sterile drape may minimise the risk of surgical wound contamination.

The triceps-flexor carpi ulnaris (TRIFCU) approach to the elbow.

INTRODUCTION: Intra-articular fractures of the distal humerus frequently require internal fixation. Several approaches have been described, with the posterior approaches being most common. We present a new approach to the distal humerus via the lateral border of the triceps muscle. PATIENTS AND METHODS: The senior author has used this technique for fixation of intra-articular fractures of the distal humerus in 12 patients. RESULTS: The approach is equally useful for intra- and extra-articular fractures. No cases of postoperative ulna nerve neuropraxia have been encountered. There have been no postoperative wound complications. The exposure has allowed sufficient access to allow anatomically contoured plates to be easily applied to both sides of the distal humerus with confirmation of intra-articular fracture reduction. CONCLUSIONS: The approach has the advantages of leaving the muscular bed of the ulna nerve undisturbed, whilst still providing excellent exposure of the distal humerus. The triceps mechanism is not divided or split allowing rapid recovery of extensor function. Additionally, because of the natural carrying angle of the elbow, repositioning of the reflected triceps aponeurosis is easy.

Biological treatment of waste gas containing mixture of monochlorobenzene (MCB) and benzene in a bench scale biofilter.

The paper outlines treatment of waste gas containing monochlorobenzene (MCB) and benzene in a mixture using biofilter packed with compost and woodchips seeded with Acinetobacter calcoaceticus. The biofilter could treat waste gas containing MCB and benzene effectively with an efficiency of (99+/-5%) and (97+/-6%) at optimal empty bed contact time (EBCT) of 3 min with a loading of 57 g/m(3)/h of MCB and 2g/m(3)/h of benzene. At optimum loading of MCB and benzene, the biofilter showed total bacterial count of 13 x 10(5)CFU/g of compost, while the MCB and benzene degrading bacterial count was 71 x 10(4)CFU/g and 5 x 10(4)CFU/g compost respectively. The experimental removal efficiency of MCB and benzene were in good agreement with the model predicted value.

Treatment of waste gas containing low concentration of dimethyl sulphide (DMS) in a bench-scale biofilter.

Biological treatment of dimethyl sulphide (DMS) was investigated in a bench-scale biofilter, packed with compost along with wood chips, and enriched with DMS degrading microorganism Bacillus sphaericus. The biofilter could remove 62-74% of the inlet DMS, at an optimum loading of 0.484 g/m(3)/h with optimum empty bed contact time (EBCT) of 384 s and an average moisture range of 65-70%. The biodegradative products of DMS were sulphide, thiosulphate and sulphate. Evaluation of microbiological status of the biofilter indicated the presence of other bacterial cultures viz. Paenibacillus polymyxa, and Bacillus megaterium, besides B. sphaericus.

An anatomic study of flexor tendon sheaths: a cadaveric study.

Previous descriptions of the pattern of communication between the digital flexor tendon sheaths have been largely based on imaging studies. An anatomic study on 12 cadaveric hands was conducted using water soluble dye and directly observed patterns of communication between the digital flexor tendon sheaths and the radial and ulnar bursae. Four out of twelve specimens (33%) demonstrated a communication between the radial and ulnar bursae. The ulnar bursa communicated with the ring finger flexor sheath in two specimens, and the index finger flexor sheath in two specimens. One hand (8.3%) showed communication between the middle finger tendon sheath and radial bursa and between the index finger flexor tendon sheath and radial bursa. These findings show a considerable level of variation in communicating patterns between the synovial sheaths of the hand and wrist. Clinicians should be aware of the possibility of variations to the classical presentation of spread of infection through the digital flexor sheaths.

Volar perilunate dislocation: a case report and review of the literature.

Perilunate dislocations, lunate dislocations and perilunate fracture dislocations are rare injuries comprising of less than 10% of all wrist injuries. Volar peri-lunate dislocations (VPLDs) account for less than 3% of perilunate dislocations. These severe carpal injuries occur after high-energy trauma to the wrist and falls on the outstretched hand. We present a case of a missed VPLD who developed parasthesia in the distribution of the median nerve 18 months after the initial injury. A plain film radiograph revealed a stage II VPLD. Nerve conduction studies confirmed compression of the median nerve at the carpal tunnel. VPLDs are extremely rare injuries. A quarter of perilunate dislocations are missed on initial presentation. The outcome is poor for missed injuries and this patient is aware that a wrist fusion may be required in the future for to treat symptoms.

How many clinic visits does it take to treat distal radial fractures?

The purpose of this study was to evaluate the changes in alignment during the course of treatment for extra-articular distal radius fracture and the relationship of initial and intermediate radiographs, with the final radiograph taken at fracture union. A cohort of 96 consecutive patients who were conservatively managed for extra-articular distal radius fracture in an 18-month period was undertaken. The radiographs analysed were taken at prereduction, postreduction, a week later and at fracture union. The radiological parameters analysed were radial tilt, radial length, radial inclination, dorsal comminution and ulnar styloid fracture. There was a significant change in radiographic alignment between initial and immediate postreduction radiographs, and between postreduction 1 week later radiographs (p < 0.05), but the number of patients in the 1 week later and fracture union groups remained similar (p > 0.05). All patients with poor radiological outcome had ulnar styloid fractures. This was also associated with dorsal comminution in 86% of patients. Patients with satisfactory radiological outcome had ulnar styloid fracture and comminution in 34% and 43% of patients respectively. The final radiological outcome was not found to be influenced by initial unsatisfactory alignment of radial tilt, radial length and radial inclination individually or in combination. We suggest that two clinic visits after initial reduction of the fracture should be sufficient to manage such injuries; the first visit 1 week after manipulation to detect unacceptable displacement and if found satisfactory, the last visit at fracture union for final review, advice and referral to physiotherapy.