Prefrontal Cortex Oxygenation Evoked by Convergence Load Under Conflicting Stimulus-to-Accommodation and Stimulus-to-Vergence Eye-Movements Measured by NIRS

Purpose: To extend our knowledge of the functional linkages between visual fatigue and regional cerebral prefrontal cortex (PFC) oxygenation, we measured time related hemodynamic changes over the right dorsolateral prefrontal cortex (dlPFC) during convergence load under conflicting stimulus-to-accommodation and stimulus-to-vergence eye movements with and without concurrent mental load.

Methods: Twenty healthy participants with a median age of 28 years (range: 18–44 years) fixated upon a vertical bar presented separately to the left and right eyes, using polarized filters, during four counterbalanced 10-min periods: (i) no accommodation/vergence conflict (Control, Ctrl); (ii) added convergence load and accommodation/vergence conflict (Conv); (iii) added cognitive load only (Cog) and; (iv) a combination of added cognitive and convergence load and accommodation/vergence conflict (Cc). Viewing distance was 65 cm. Non-invasive measurements of hemodynamic activity over the dlPFC were quantified by functional near-infrared spectroscopy (fNIRS). During the two-convergence load conditions, the horizontal disparity of the two bars varied dynamically from no disparity to a disparity set 20% below the individual threshold for diplopia. Cognitive load was induced by the n-back-2 test which required the subject to memorize and recall the changing colors of the horizontal bars and decide when a given color was the same as that occurring two colors previously. fNIRS data were averaged over 10-s windows centered at 0, 2, 4, 6, 8, and 10 min of each task, subtracted from a 20-s baseline window immediately preceding the visual task, and then represented as changes in oxygenated hemoglobin (ΔHbO₂)_, deoxygenated hemoglobin (ΔHHb) and total hemoglobin (ΔtHb).

Results: Linear mixed model analyses showed that hemodynamic activity was systematically influenced by time (p < 0.001). The group-averaged time-related level of change across the viewing conditions did not differ when compared with one another (p > 0.05). Larger convergence eye-movement responses under conflicting stimulus-to-accommodation, and stimulus-to-vergence over time, increased ΔHbO₂ and ΔtHb only in condition Cc and after 8 min of task time (p < 0.10 for min^-6 and min^-8: p < 0.05 for min^-10).

Discussion: Collectively, our data suggest that HbO₂, HHb, and tHb, recorded over the dlPFC with fNIRS, can be used to assay the degree to which supervisory oculomotor control processes are activated during visually deficient near work.

Trapezius muscle activity increases during near work activity regardless of accommodation/vergence demand level

Aim

To investigate if trapezius muscle activity increases over time during visually demanding near work.

Methods

The vision task consisted of sustained focusing on a contrast-varying black and white Gabor grating. Sixty-six participants with a median age of 38 (range 19–47) fixated the grating from a distance of 65 cm (1.5 D) during four counterbalanced 7-min periods: binocularly through −3.5 D lenses, and monocularly through −3.5 D, 0 D and +3.5 D. Accommodation, heart rate variability and trapezius muscle activity were recorded in parallel.

Results

General estimating equation analyses showed that trapezius muscle activity increased significantly over time in all four lens conditions. A concurrent effect of accommodation response on trapezius muscle activity was observed with the minus lenses irrespective of whether incongruence between accommodation and convergence was present or not.

Conclusions

Trapezius muscle activity increased significantly over time during the near work task. The increase in muscle activity over time may be caused by an increased need of mental effort and visual attention to maintain performance during the visual tasks to counteract mental fatigue.

Improved recovery after music and therapeutic suggestions during general anaesthesia: a double-blind randomised controlled trial

PURPOSE

This study was designed to determine whether music or music in combination with therapeutic suggestions in the intra-operative period under general anaesthesia could improve the recovery of hysterectomy patients.

METHODS

In a double-blind randomised clinical investigation, 90 patients who underwent hysterectomy under general anaesthesia were intra-operatively exposed to music, music in combination with therapeutic suggestion or operation room sounds. The anaesthesia was standardised. Postoperative analgesia was provided by a patient-controlled analgesia (PCA). The pain scores were recorded by means of a visual analogue scale. Nausea, emesis, bowel function, fatigue, well-being and duration of hospital stay were studied as outcome variables.

RESULTS

On the day of surgery, patients exposed to music in combination with therapeutic suggestions required less rescue analgesic compared with the controls. Patients in the music group experienced more effective analgesia the first day after surgery and could be mobilised earlier after the operation. At discharge from the hospital patients in the music and music combined with therapeutic suggestion group were less fatigued compared to the controls. No differences were noted in nausea, emesis, bowel function, well-being or length of hospital stay between the groups.

CONCLUSION

This double-blind study has demonstrated that intra-operative music and music in combination with therapeutic suggestions may have some beneficial effects on postoperative recovery after hysterectomy. Further controlled studies are necessary to confirm our results.

Differences in risk factor patterns between cervical and trochanteric hip fractures. Swedish Hip Fracture Study Group

The two types of hip fracture--cervical and trochanteric femoral fractures--are generally considered together in etiologic studies. However, women with a trochanteric fracture may be more osteoporotic than those with cervical hip fractures, and have higher post-fracture mortality. To explore differences in risk factor patterns between the two types of hip fracture we used data from a large population-based case-control study in Swedish women, 50-81 years of age. Data were collected by questionnaire, to which more than 80% of subjects responded. Of the cases included, 811 had had a cervical fracture and 483 a trochanteric fracture during the study period; these cases were compared with 3312 randomly selected controls. Height and hormonal factors appeared to affect the risk of the two types of hip fracture differently. For every 5 cm of current height, women with a cervical fracture had an adjusted odds ratio (OR) of 1.23 (95% CI 1.15-1.32) compared with an OR of 1.06 (95% CI 0.97-1.15) for women with trochanteric fractures. Later menopausal age was protective for trochanteric fractures (OR 0.95, 95% CI 0. 91-0.99 per 2 years) but no such association was found for cervical fractures. Compared with never smokers, current smokers had an OR of 1.48 (95% CI 1.12-1.95) for trochanteric fractures and 1.22 (95% CI 0.98-1.52) for cervical fractures. Current hormone replacement therapy was similarly protective for both fracture types, but former use substantially reduced risk only for trochanteric fractures: OR 0. 55 (95% CI 0.33-0.92) compared with 1.00 (95% CI 0.71-1.39) for cervical fractures. These risk factor patterns suggest etiologic differences between the fracture types which have to be considered when planning preventive interventions.

Histology corresponding to mildly dyskaryotic smears--a study of 190 laser cone biopsied patients

OBJECTIVES

The aim of the study was to evaluate the histological outcome of laser ring biopsies in patients with one or more smears showing cytological mild dyskaryosis where punch biopsies were not performed. The possibilities of predicting histological findings of CIN 2 and CIN 3 were analyzed.

METHODS

The study comprised 190 laser ring biopsied patients with mildly dyskaryotic smears. Eighty-five patients were excluded from the initial 275 because of up- and downgrading of smears. Conization specimens and smears were reviewed by an experienced histopathologist and two experienced cytotechnicians. The histological findings were correlated to smear findings.

RESULTS

Histologically, CIN 2 was found in 60 and CIN 3 in 45 patients (31 and 24%, respectively). The incidence of histological CIN 3 was higher in those with two or more mildly dyskaryotic smears and in those dyskaryotic smears lacking koilocytic change. Mildly dyskaryotic smears without endocervical cells indicated higher incidence of histological CIN 3. The fact that 36 of 96 CIN 2 and 3 lesions (38%) involved only 3 mm or less of the mucosa might be one important explanation for the absence of representative cells in the corresponding smears.

CONCLUSIONS

Our study has shown that a mildly dyskaryotic smear is a strong indicator of CIN 2-3 histologically, especially in those cases without koilocytic cells and in those with repeatedly abnormal smears. The importance of inadequate sampling is indicated by higher incidence of histological CIN 3 in those with less than optimal smears. These findings are some of the factors to be taken into account when planning treatment strategies for this group of patients.

Cervex-Brush vs. spatula and Cytobrush. A cytohistologic evaluation

OBJECTIVE

To compare the efficacy of two cervical smear instruments, Cervex-Brush and spatula plus Cytobrush.

STUDY DESIGN

Cervical smears were taken before laser ring biopsies in 213 women, who were randomized for the Cervex-Brush or spatula plus Cytobrush (S+C). The cytologic diagnosis was compared to the histologic diagnosis after laser ring biopsy.

RESULTS

The correlation between cytology and histology showed comparable concordance (54% and 42%) for the two devices. In 130 (74 with Cervex-Brush and 56 S+C) patients, histology revealed moderate dysplasia or more advanced lesions. Those cases were further analyzed for smear failures. Negative smears were found in 13 cases (10 in the Cervex-Brush and 3 in the S+C group). This difference in favor of S+C was not, however, statistically significant. Significantly more false negative smears were found when endocervical cells were absent and in patients 30-39 years of age.

CONCLUSION

Modern sampling devices, such as the Cervex-Brush and S+C, seem to be equally efficient in obtaining dysplastic squamous cells. Other factors of importance for nonrepresentative cervical smears should be studied in order to improve efficacy.

Fixation of femoral neck fracture. A randomized 2-year follow-up study of hook pins and sliding screw plate in 222 patients

We compared fixation with hook pins or sliding screw plate in a prospective randomized study of 222 patients with a cervical hip fracture. Radiographic evidence of early redisplacement, nonunion, or late segmental collapse was found in 43 of 122 patients operated on with two hook pins and in 40 of 100 patients operated on with the sliding screw plate. According to the actuarial method, the failure rate after 2 years was 38% with hook pins and 46% with screw plates, which not is a significant difference. Due to early redisplacement, reoperation with an endoprosthesis was performed within 0.5 (2) years in 11 (22) patients in the hook-pin group and in 4 (17) patients in the sliding-screw plate group.

Bone mineral content and fixation strength of femoral neck fractures. A cadaver study

We measured the bone mineral content (BMC) of 21 human femoral autopsy specimens using Radiographic Attenuation Technique (RAT). The specimens were then tested for stiffness in a material-testing machine. Osteosynthesis was performed after medial femoral neck osteotomy, using 1 of 3 different pinning methods: 2 hook pins (LIH), 2 cannulated screws (Uppsala), and 3 cannulated screws (CHP). The specimens were allocated to each method by grouping them in triplets with similar BMC. Cyclic loading at 500-1000 N and 1 Hz was performed during 50 minutes. The amount of axial compression during loading was measured. Finally, loading to failure was done and post-fixation stiffness and ultimate compression strength recorded. With one exception, all cases failed where the BMC was less than 0.4 g/cm2. No differences between the methods of osteosynthesis were found. The fixation strength was mostly dependent on the strength of the bone, i.e., the degree of osteoporosis.

Health status and risk for hip fracture: a case control study of 70–75-year-olds

A study concerning health status and social factors was performed of all hip fracture patients (n = 868) admitted to the orthopaedic clinics in Gothenburg, Sweden, during the course of 1 year. All non-institutionalized patients aged 70-75 years were invited 6 months after the fracture to a case-control survey with age-matched controls from the gerontological studies in Gothenburg. The hip-fracture patients had lower body mass index (BMI), lower bone mineral content (BMC) and higher prevalence of vertebral compression fractures. The serum concentrations of osteocalcin, aminoterminal peptide from procollagen-III and alkaline phosphatase activity were higher in the fracture group while serum creatinine concentrations and muscle strength were significantly lower. The prevalences of previous stroke and of Parkinsonism were greater in the hip fracture group. No differences in medication were observed. Thirty-nine percent of the hip fracture patients were suffering from pain and 88% had some form of walking disability at the follow-up study.

Osteoporosis and back pain in the elderly. A controlled epidemiologic and radiographic study

The incidence of back pain was investigated in hip fracture patients, 50-99 years of age, and in 70-, 75-, and 81-year-old controls from the same population. The prevalence of vertebral fractures were evaluated from spinal radiographs. Eighty hip fracture patients and 103 controls, all between 70 and 75 years of age, were included in the radiographic study. The incidence of back pain of the controls was twice that of the hip fracture patients, 45-48% compared with 23-20%, respectively, for both female and male subjects. Conversely, vertebral fractures were radiographically shown in 43% of the hip fracture patients and in 22% of the controls. Thus, the major explanation for longstanding back pain in the elderly does not appear to be related to spinal osteoporosis.

Isometric muscle strength and quantitative electromyography of back muscles in wrestlers and tennis players

The isometric motor performance of the trunk muscles was studied in 10 male wrestlers and 9 male tennis players, all of whom were elite athletes. Isometric flexion, extension, and lateral bending were performed. The motor output, including fatigue, was studied by means of a load cell and using electromyography. The wrestlers were found to have symmetrical strength and were stronger in all measured directions, especially in side bending (flexion, 852 N; extension, 951 N; right and left side bending, 759 N and 744 N, respectively), than the tennis players and normal subjects of any published study. The development of fatigue in the erector spinae muscles, as evaluated by spectral analysis of the myoelectric signal, was not symmetrical and was significant bilaterally at the lumbar level and on the right side at the thoracic level. As expected, the tennis players had asymmetrical isometric strength. They were stronger in left side bending than right side bending (643 N compared with 557 N, P less than 0.01), and stronger in extension than flexion (835 N compared with 638 N, P less than 0.01). The development of fatigue in the erector spinae muscles was significant bilaterally at the lumbar level and on the left side at the thoracic level. The development of fatigue in the tennis players was less than that of the wrestlers except for the left thoracic measurement site. Our conclusions are that tennis players appear to be relatively weak in trunk flexion. The wrestlers displayed a development of fatigue that was asymmetrical and was of nearly the same degree as the tennis players, but on the opposite side.

[The standard hip--evaluation of physical function and health care utilization following hip fracture]

All 441 cases of hip fracture admitted to Sahlgrenska sjukhuset, Göteborg, during a one-year period were followed in accordance with a form developed by the Swedish Medical Research Council. Osteosynthesis was the method used in over 97 per cent of the cases. There were 336 women, mean age 80.0 (+/- 9.9) years, and 105 men, mean age 77.1 (+/- 11.8). A rehabilitation programme for non-institutionalised patients (68 per cent of the total of 441) reduced the length of stay at the orthopaedic department from 22 days to an average of 15 days in 1986, and the proportion of patients able to return home was increased from 81 per cent in 1982 to 90 per cent in 1987-88. Thus, the use of rehabilitation or nursing home facilities was reduced, and the length of stay there was reduced. The findings of the study also showed the rehabilitation to be time-consuming, and that few hip fracture patients ever regain complete pre-fracture function. Therefore it is suggested that the follow-up should be extended to cover a longer period than four months. Otherwise, the form is well designed, and its use improves the comparability of different studies.

Internal fixation of femoral neck fracture. No difference between the Rydell four-flanged nail and Gouffon's pins

Two methods of internal fixation of femoral neck fractures were compared in a prospective randomized study of 223 patients. Radiographic evidence of early redisplacement, nonunion, or late segmental collapse occurred in 45 of 122 patients operated on with the Rydell four-flanged hook nail and in 33 of 101 patients operated on with Gouffon pins. According to the actuarial method of follow-up, the failure rates after 2 years were respectively 41 and 35 percent in the nail and pin groups, which is a nonsignificant difference.

Ten-year survival after fractures of the proximal end of the femur

Two hundred and eighty-eight patients who sustained a fracture of the proximal end of the femur in 1975 were followed up for 10 years. The mean age of the patients was 75 years. Seventy-two percent were women. Age was the single most important factor determining long-term survival. Other important factors were category of accommodation, sex and place of injury. After 10 years only 1.4% of the patients discharged to an institution were alive compared to 40% of the patients discharged to their own homes.

Stability of fixation in femoral neck fractures. Comparison of four fixation devices in vivo and in cadavers

On human cadaveric femora, internal fixation of cervical osteotomies was performed with four different devices. With the use of a lever, a static force was applied through the acetabulum to the osteotomy site. Motion at the osteotomy site was measured by two strain gauges. The compression force necessary to inhibit motion at the osteotomy site during the fixation procedure was measured. This force was lower with a hook pin than with the other devices. During surgery in 12 patients with displaced femoral neck fractures, the forces holding the fracture surfaces together were measured with a dynamometer. The force at which widening of the fracture gap was observed by fluoroscopy was recorded. In seven fractures, the mean compression force was 110 (60-170) N. The remaining five fractures did not open up when pressures of up to 200 N were applied. These forces were always greater than the hook pin forces measured in the cadaver experiments, but often less than the forces obtained with the other devices.

Incidence of hip fracture in western Sweden 1974-1982. Comparison of rural and urban populations

Several epidemiological studies in northern Europe have shown that fractures in the elderly exceed the expected increase in the aging populations. We have compared the incidence of hip fracture in the rural county of Skaraborg and the city of Göteborg in Sweden. After adjustment for age changes in the population, the incidence of hip fracture in Skaraborg County was lower than in Göteborg during the period 1974-1984. The non-age-related increase in the incidence of fractures found in the city was not confirmed in the rural area.

Electromyographic studies of the lumbar trunk musculature during the development of axial torques

The myoelectric activity of selected trunk muscles at the L3 level was studied during the development of a controlled isometric axial torque. Muscle activity was recorded with surface electrodes bilaterally over the erector spinae muscles, the rectus abdominus, the obliques externus, and the obliques internus. Subjects applied graded isometric axial torque efforts with the addition of a Valsalva. The largest myoelectric activities were recorded over the obliques externus and internus. The side of the muscle developing the torque did show the greatest myoelectric activity, but considerable antagonistic activity was also present. Neither the rectus abdominus nor the internal oblique muscles showed any difference from side to side. The calculated forces in the rectus abdominus and the erectores spinae were high, suggesting that a considerable amount of the muscle contraction was used to control the posture. A Valsalva did not decrease myoelectric activity, but did increase the torque developed.

Reoperations of hip fractures

The incidence and type of reoperations after osteosynthesis of cervical and trochanteric femoral fractures in the city of Göteborg, Sweden was studied from 1965 through 1981. The yearly incidence of reoperations decreased for both types of fractures over the years. Reoperations after cervical fractures were frequent, occurring in about 30 per cent. There were few reoperations after trochanteric fractures on the other hand, 3.6 per cent in 1981. Arthroplasties comprised the greatest number of reoperations, with a fairly constant relative frequency of about 18 per cent during the study period.

Impaired muscle function with aging. A background factor in the incidence of fractures of the proximal end of the femur

Muscle biopsy material from vastus lateralis musculus quadriceps was obtained during surgery from 43 66-100-year-old female and nine 70-89-year-old male patients with fresh hip fractures. Before the accident, 18 women and two men were clinically healthy, and in the others, one-third had cardiovascular, one-third locomotor, and one-third neurologic disorders. Twelve women lived in institutions. The other women and all of the men lived in their own homes. A striking finding was a more advanced reduction in muscle fiber size in the vastus lateralis, especially in the fast twitch (FT) fibers. The reduction occurred in preaccident clinically healthy fracture patients. With advancing age, the proportions of the slow twitch (ST) and FT fibers remained the same. Well-maintained, enzymatic metabolic capacity, moderate neuropathic changes, and absence of myopathic changes indicate that the quality of the muscle tissue is relatively well preserved, even in elderly patients with hip fractures. Muscle fiber atrophy and weakness in muscle strength may be attributable in part to a low physical activity and are possibly reversible with exercise in some individuals.

Epidemiology of hip fractures in Göteborg, Sweden, 1940-1983

A dramatic progressive increase in the incidence of cervical and trochanteric fractures of the proximal end of the femur was observed in Göteborg from 1940 to 1983. From 1965 through 1983, the fracture rate increased by 109%. Only 20% of the increase can be explained by the age factors in the population. With the present trend, which appeared to be validated by the observed fracture rate from 1981 to 1983, the fracture incidence would double in 16 years in men and in 30 years in women.

Electromyography of the paravertebral muscles in idiopathic scoliosis. Measurements of amplitude and spectral changes under load

The myoelectric activity of the paraspinal muscles was recorded in girls with idiopathic scoliosis and in healthy controls. The muscles of the back were loaded isometrically and the signals recorded at the T8 and L3 levels were analysed as regards amplitude and frequency. A comparatively higher signal amplitude was found on the convex side of the scoliosis curve. This was found to be due to a lower amplitude on the concave side when the scoliosis group was compared to the controls. The amplitude difference was correlated to the degree of scoliosis. A shift in the myoelectric spectrum toward lower frequencies occurred during the loading period. There were no differences in this respect between the sides of the scoliosis, nor were there differences between the scoliosis patients and the controls. Secondary adaptation to the higher load demand by the muscles on the convex side in scoliosis is the most probable explanation for our observations.

Is there a change in relative muscle fibre composition with age?

Muscle biopsy was taken from the vastus lateralis muscle during surgery of recent fractures of the neck of the femur in 52 patients aged 66-100 years. The percentage of slow twitch (ST) fibres was close to 55% with no significant change with age and no difference between patients with and without clinical diagnoses prior to the fracture. Also subgrouping of fast twitch (FT) fibres showed insignificant changes in this age range. Muscle fibre areas were smaller for FT than for ST fibres. A comparison between proximal and distal sampling site in the muscle did not show any significant difference. Combining these results and previous results from our laboratories no change in relative fibre composition with age could be proven.

Relation of intramuscular pressure to the force output and myoelectric signal of skeletal muscle

The force output of the biceps brachii muscle during static isometric contractions was studied in 26 arms of 23 subjects in relation to the simultaneously recorded level of the electromyogram (EMG) and the intra-muscular pressure (IMP). The EMG was picked up with wire electrodes and the IMP recorded through wick catheters or by infusion technique. The load at the wrist was monitored using a force transducer. A near linear relationship with correlation coefficients exceeding 0.96 was shown between the load on the wrist on the one hand and IMP and EMG on the other. The regression coefficients of the relation between the load and IMP or EMG varied considerably between individuals and between different measuring points in the same individual. In cases where the correlation between the wrist load on one hand and the IMP and EMG on the other was poor because of varying synergistic interaction between the flexor muscles, the EMG and IMP were always well correlated. This means that they change in the same way when the mechanical output of the muscle varies. This was also the case in three experiments where the IMP and EMG from all three elbow flexors were recorded while the subjects changed from a supinated to a pronated position supporting a constant load on the wrist. Considering these observations we present indirect evidence that IMP and the level of the EMG signal both are good estimators of isolated muscular force under isometric static conditions and over limited time.

Postural and time-dependent effects on body height and scoliosis angle in adolescent idiopathic scoliosis

Changes in body height and scoliosis angle under the influence of gravity were studied in 40 patients with adolescent scoliosis. The average decrease in body height was 1% during a day. There were no significant changes in the mean angles of the scoliosis curves during the day. The patients were grouped according to age, standing and sitting heights, weight and skeletal maturation. A decrease in the scoliosis angles occurred in younger, more skeletally immature and lighter individuals, while an increase occurred in older, more skeletally mature and heavier individuals. The difference between the scoliosis angles measured from standing and supine views was also analyzed. The correction of the scoliosis angle in the supine position was on average 19%. No correlation was found between the change in angle and any of the growth factors studied. There was also no correlation between the change in angle and the degree of curvature.

Morphology of the paravertebral muscles in adolescent idiopathic scoliosis

Histochemical studies of paravertebral muscles in idiopathic scoliosis have shown a consistently higher proportion of type I fibers on the convex side. In this study of the transversospinal muscles in moderate idiopathic scoliosis, we could demonstrate a lower type II B/II A fiber ratio on the convex side, along with an increased proportion of type I fibers. The capillary count was also higher on the convex side, especially around the type I fibers. The few pathologic changes found were predominately seen in the gravest cases of scoliosis. It is concluded that the fiber type distribution, capillary count, and metabolic enzyme activity on the convex side resembles that seen after endurance training. This suggests a secondary adaptive origin of these changes.

Fractures of the proximal end of the femur in Göteborg, Sweden, 1940-1979

A total of 3475 fractures of the proximal femur occurring in Göteborg. Sweden, in 1965, 1969, 1970, 1975, 1978 and 1979 were reviewed, and the information obtained was compared with earlier published epidemiologic data from Göteborg presented by Mårtensson (1962) for the years 1940-1959. A highly statistically significant age specific increase in fracture incidence was found for trochanteric as well as cervical fractures, and for both women and men. The fracture incidence increased from about 3 per 1000 in 1965 to 5 per 1000 in 1979, and the yearly number of fractures in this city from 104 in 1940 to 788 in 1979. With the present trend the fracture incidence will double over the next 20 years.

Subcapital fractures of the femur. Re-operations with internal fixation

Over a period of 5 years, 55 re-operations with internal fixation were performed on 51 patients. The re-operations constituted 9.2 per cent of all operations employing internal fixation for subcapital fractures of the femur during that period. The indications for re-nailing were penetration of the nail through the femoral head, or slipping of the nail, with or without dislocation of the fracture. Only 26 per cent of the re-nailed fractures healed. Seventy-three per cent showed avascular necrosis and 61 per cent non-union.