The primary aim of this study was to identify the rate of osteoarthritis in scaphoid fracture non-union. We also aimed to investigate whether the incidence of osteoarthritis correlates with the duration of non-union(interval), and to identify the variables that influence the outcome. We retrospectively reviewed 273 scaphoid fracture non-union presented between 2007 and 2016. Data included patient demographics, interval, fracture morphology, grade of osteoarthritis (Kellgren-Lawrence) and scaphoid non-union advanced collapse (SNAC), and overall health-related quality of life. Patients were divided into two groups (SNAC and Non-SNAC). Group differences were analysed using Mann-Whitney U test and association with Pearson's correlations. A two-sided p-value of <0.05 was considered significant.

The scaphoid fracture non-union were confirmed on CT scans (n=243) and plain radiographs (n=35). The subjects were 32 females and 260 males with the mean age of 33.8 years (SD, 13.2). The average interval was 3.1 years (range, 0–45 years). Osteoarthritis occurred in 58% (n=161) of non-unions, and 42% (n=117) had no osteoarthritis. In overall, 38.5% (n=107) had SNAC-1, 9% (n=25) with SNAC-2, and 10.4% (n=29) presented with SNAC-3. The mean interval in the non-SNAC group was 1.2 years, and in SNAC 1,2, and 3 were 2.6, 6.8, and 11.1 years, respectively. The average summary index in SNAC and non- SNAC groups was 0.803 and 0.819, respectively. Our results also showed a significant correlation between advanced osteoarthritis and proximal fracture non-unions(P<0.05).

We concluded that there is no clear correlation between the interval and the progression of osteoarthritis. SNAC was more likely to occur in fractures aged 2 years or older.

We report the outcome at a mean of 93 months (73 to 110) of 71 patients with an acute fracture of the scaphoid who were randomised to Herbert screw fixation (35) or below-elbow plaster cast immobilisation (36). These 71 patients represent the majority of a randomised series of 88 patients whose short-term outcome has previously been reported. Those patients available for later review were similar in age, gender and hand dominance.

There was no statistical difference in symptoms and disability as assessed by the mean Patient Evaluation Measure (p = 0.4), or mean Patient-Rated Wrist Evaluation (p = 0.9), the mean range of movement of the wrist (p = 0.4), mean grip strength (p = 0.8), or mean pinch strength (p = 0.4).

Radiographs were available from the final review for 59 patients. Osteoarthritic changes were seen in the scaphotrapezial and radioscaphoid joints in eight (13.5%) and six patients (10.2%), respectively. Three patients had asymptomatic lucency surrounding the screw. One non-operatively treated patient developed nonunion with avascular necrosis. In five patients who were treated non-operatively (16%) there was an abnormal scapholunate angle ( > 60°), but in four of these patients this finding was asymptomatic.

No medium-term difference in function or radiological outcome was identified between the two treatment groups.

The benefits and risks of early fixation of scaphoid fractures were investigated in 88 patients in the working age group with clear bicortical fractures. Patients were randomised using a random number sheet into 44 who had early internal fixation using a Herbert Screw without a cast and 44 who were treated conservatively in a Colles’ type plaster cast for eight weeks. Patients were reviewed at 2,8,12,26 and 52 weeks with pain severity, tenderness, swelling, wrist movement, grip strength, the Patient Evaluation Measure (PEM) outcome score and x-rays assessed at each visit.

There was no difference between groups for age, sex, nature of injury, dominance, side injured or type of scaphoid fracture. The two groups were similar for pain severity at each of the intervals. Eight of the conservative group and one fracture in the operated group did not unite (p=0.01).

At the 8th and 12th week visits the operated group was better than those treated in a cast for wrist range, grip strength and PEM score (less is better). Thereafter there was no difference between groups.

Patients operated on returned to work at a mean of 6 weeks after their injury compared to 11 weeks for those treated conservatively. There were no serious complications, 6 patients had hypertrophic or itchy scars and one had hypoaesthesia in the palmar cutaneous branch of the median nerve distribution.

Early fixation of scaphoid fractures can be offered as an alternative to cast immobilisation with good early benefits and low risk, however the surgery can be technically difficult.

The different attributes of the Patient Evaluation Measure (PEM) questionnaire were investigated in 80 patients with a fracture of the scaphoid. Assessments were made at 2, 8, 12, 26 and 52 weeks. Reliability was assessed by measurement of the internal consistency of the different questions in 275 completed PEM forms.

Cronbach’s alpha, which needs to lie between 0.7 and 0.9, was 0.9 for the PEM. Pain, tenderness, swelling, wrist movement and grip strength correlated with the PEM score confirming the validity of the assessment. Changes in the different variables between visits correlated significantly with changes in the PEM score; its effect size and standardised response mean were comparable to those of grip strength and movement, confirming the responsiveness of this questionnaire. Gender, dominance and the side injured did not influence the scores. Older patients had a poorer outcome as assessed by the score which appeared to be a true effect and not age bias. Our study confirmed that the PEM is a reliable, valid and responsive instrument in assessing outcomes of disorders of the hand.