Patterns of healing of scaphoid fractures. The importance of vascularity.
We studied 45 patients with 46 fractures of the scaphoid who presented sequentially over a period of 21 months. MRI enabled us to relate the pattern of the fracture to the blood supply of the scaphoid. Serial MRI studies of the four main patterns showed that each followed a constant sequence during healing and failure to progress normally predicted nonunion. (+info)
Acute fractures of the scaphoid. Treatment by cast immobilisation with the wrist in flexion or extension?
Acute fractures of the scaphoid were randomly allocated for conservative treatment in a Colles'-type plaster cast with the wrist immobilised in either 20 degrees flexion or 20 degrees extension. The position of the wrist did not influence the rate of union of the fracture (89%) but when reviewed after six months the wrists which had been immobilised in flexion had a greater restriction of extension. We recommend that acute fractures of the scaphoid should be treated in a Colles'-type cast with the wrist in slight extension. (+info)
Skeletal maturity in Pakistani children.
Skeletal maturity in 750 normal Pakistani children (400 males, 350 females) aged 1-18 y was determined by the Greulich-Pyle atlas system. Male children during first year and female children during first 2 y of life matured in conformity with Greulich-Pyle standards. After that period mean bone ages were lower than the American standards up to 15 y in males and 13 y in females (at or around puberty), which may be due to malnutrition, ill health or other environmental factors. After puberty bone ages were higher than the American standards indicating earlier maturity in Pakistani than Western children. Hence for the proper evaluation of skeletal age in a given region, a longitudinal study on individuals in that region to establish normal standards is necessary. (+info)
The relationship between the site of nonunion of the scaphoid and scaphoid nonunion advanced collapse (SNAC).
We studied retrospectively the radiographs of 33 patients with late symptoms after scaphoid nonunion in an attempt to relate the incidence of scaphoid nonunion advanced collapse (SNAC) to the level of the original fracture. We found differing patterns for nonunion at the proximal, middle and distal thirds. The mean intervals between fracture and complaint were 20.9, 6.7 and 12.6 years and obvious degenerative changes occurred in 85.7%, 40.0% and 33.3%, for the six proximal-, eight middle- and two distal-third nonunions, respectively. Nonunion at the proximal and middle thirds showed the first degenerative changes at the radioscaphoid joint, and this was followed by narrowing of the scaphocapitate and then the lunocapitate joints. In our two nonunions of the distal third degenerative changes were seen only at the lunocapitate joint. Most patients with SNAC and nonunion of the middle or distal third showed dorsal intercalated instability; few patients with nonunion of the proximal third developed this deformity. We discuss the initial management of nonunion of the scaphoid at different levels in the light of our findings, and make recommendations. (+info)
Kinematics of the wrist. Evidence for two types of movement.
We enrolled 34 normal volunteers to test the hypothesis that there were two types of movement of the wrist. On lateral radiographs two distinct patterns of movement emerged. Some volunteers showed extensive rotation of the lunate with a mean range of dorsiflexion of 65 degrees, while others had a mean range of 50 degrees. The extensive rotators were associated with a greater excursion of the centre of articulation of the wrist. It is suggested that dynamic external fixation of a fracture of the distal radius carries with it the risk of stretching the ligaments or causing volar displacement at the site of the fracture. (+info)
The treatment of pseudoarthrosis of the scaphoid by bone grafting and three methods of internal fixation.
OBJECTIVES: To measure the rate of union in patients with pseudoarthosis of the scaphoid, treated with trapezoidal bone grafting as outlined by Fernandez and 1 of 3 methods of internal fixation and to compare unions versus nonunions and potential predictors of union to determine if associations exist. DESIGN: A retrospective radiologic study of scaphoid pseudoarthroses. SETTING: Division of Orthopedic Surgery, Ottawa Hospital, General Site, a tertiary care facility. PATIENTS: Thirty-four patients with nonunion of scaphoid fractures, treated between 1990 and 1997, with an average follow-up of 19.8 months. INTERVENTIONS: Trapezoidal bone grafting and internal fixation with Kirschner (K) wires, an AO cannulated screw or a Herbert screw. OUTCOME MEASURES: The time to union of scaphoid pseudoarthroses and predictors of union, including the classification, location of pseudoarthrosis, type of internal fixation and length of bone graft. RESULTS: The results showed a correlation between the classification and location of the fracture as determined radiologically, and the outcome. There was no correlation between the type of internal fixation used and the outcome, or between the length of the bone graft and the outcome. Twenty-three patients had radiologically demonstrated union after a mean time of 8.2 months; 16 of 24 patients achieved successful union when treated with K-wire implants, after a mean time of 7.2 months. CONCLUSIONS: Trapezoidal bone grafting and internal fixation with K wires is a practical technique, classification and location of the fracture notwithstanding. Time to union is long, and the results may be unpredictable. Use of K wires for internal fixation presents the clinician with an alternative to fixation with either the AO cannulated screw or the Herbert screw, and has the advantages of cost, ease of insertion and accessibility. This method may therefore be the treatment of choice in developing countries. Resection of the area of pseudoarthrosis must include all fibrous tissue and sclerotic bone. The length of graft, within the parameters of this study, did not affect the outcome. (+info)
Scaphoid fracture. Review of diagnostic tests and treatment.
OBJECTIVE: To help make diagnosis and treatment of scaphoid fracture more precise by review of published evidence. QUALITY OF EVIDENCE: MEDLINE was searched using the terms "scaphoid," "carpal navicular," "fracture," "computed tomography," "bone scan," and "scintigraphy." Most papers were case-series observational reports. Papers were cited if the case series was large or if there was a high degree of agreement among several observers. The main recommendation for change in treatment of scaphoid fracture is based on two randomized clinical trials involving more than 1000 patients with proven scaphoid fracture. MAIN MESSAGE: Fracture of the scaphoid requires a specific mechanism of injury. "Snuffbox" tenderness is not specific for scaphoid fracture and is not the most useful physical finding; other physical findings provide more specific evidence for or against scaphoid fracture. Physical examination remains the basis of initial treatment and should be thorough and meticulous. X-ray films must be of high quality and should be examined carefully for bone and soft tissue signs of fracture. A Colles'-type short arm cast is adequate for treating common undisplaced scaphoid waist fractures; the thumb need not be immobilized. For suspected scaphoid fractures, without radiologic evidence of fracture, treating symptoms is likely sufficient. CONCLUSION: Evidence found in the literature can be used to improve diagnostic accuracy for scaphoid fractures, to optimize treatment for these injuries, and to reduce unnecessary immobilization and disability for patients. (+info)
Distinct missense mutations of the FGFR3 lys650 codon modulate receptor kinase activation and the severity of the skeletal dysplasia phenotype.
The fibroblast growth factor-receptor 3 (FGFR3) Lys650 codon is located within a critical region of the tyrosine kinase-domain activation loop. Two missense mutations in this codon are known to result in strong constitutive activation of the FGFR3 tyrosine kinase and cause three different skeletal dysplasia syndromes-thanatophoric dysplasia type II (TD2) (A1948G [Lys650Glu]) and SADDAN (severe achondroplasia with developmental delay and acanthosis nigricans) syndrome and thanatophoric dysplasia type I (TD1) (both due to A1949T [Lys650Met]). Other mutations within the FGFR3 tyrosine kinase domain (e.g., C1620A or C1620G [both resulting in Asn540Lys]) are known to cause hypochondroplasia, a relatively common but milder skeletal dysplasia. In 90 individuals with suspected clinical diagnoses of hypochondroplasia who do not have Asn540Lys mutations, we screened for mutations, in FGFR3 exon 15, that would disrupt a unique BbsI restriction site that includes the Lys650 codon. We report here the discovery of three novel mutations (G1950T and G1950C [both resulting in Lys650Asn] and A1948C [Lys650Gln]) occurring in six individuals from five families. Several physical and radiological features of these individuals were significantly milder than those in individuals with the Asn540Lys mutations. The Lys650Asn/Gln mutations result in constitutive activation of the FGFR3 tyrosine kinase but to a lesser degree than that observed with the Lys540Glu and Lys650Met mutations. These results demonstrate that different amino acid substitutions at the FGFR3 Lys650 codon can result in several different skeletal dysplasia phenotypes. (+info)