Knee injuries related to sports in young adult males during military service - incidence and risk factors.

The population-based incidence and risk factors for knee injuries in young adults were assessed in Finnish male conscripts performing their compulsory military service (n = 128,584). The main outcome variables were (1) hospitalization due to knee injuries overall and (2) hospitalization due to knee disorders as categorized into specific International Classification of Diseases, tenth revision diagnoses (cruciate and collateral ligament tears, meniscal tears, traumatic chondral lesions, and patellar dislocations). Person-time injury-incidence rates were calculated by dividing the number of persons with a diagnosed knee injury by the total exposure time of 97,503 person-years. The number of subjects with surgical operations and military service class changes indicative of longer term notable disability are also reported. Risk factor analyses were performed by logistic regression. The person-based incidence of hospitalizations for knee injury was 11 cases per 1000 person-years [95% confidence interval (CI): 10.4-11.7]. The most important risk factors were higher age (odds ratio 1.7; 95% CI: 1.3-2.2) and obesity (odds ratio 1.6; 95% CI: 1.03-2.5). Two thirds of all subjects hospitalized for knee injuries had surgery, and one third had longer term notable disability. These findings indicate that knee injuries cause a significant burden of hospitalizations, often leading to surgery and longer term disability.

Can orthotic insoles prevent lower limb overuse injuries? A randomized-controlled trial of 228 subjects.

Lower limb overuse injuries are common among people who are exposed to physical stress. Orthotic shoe insoles are widely used to prevent lower limb overuse injuries. Here, we conducted a randomized-controlled study to examine whether the use of orthotic insoles prevents lower limb overuse injuries. Participants (n=228) were randomly assigned to use (n=73) or not to use (n=147) orthotic insoles. The insoles were molded to the shape of the foot to provide support during physical activity. The main outcome measure in the present study was the physician-diagnosed lower limb overuse injury. Thirty-four (46.6%) subjects in the insole group were diagnosed with a lower limb overuse injury compared with 56 (38.1%) in the control group (P=0.29) during the 6-month study period. When body mass index and the results of a 12-min running test and muscle strength were adjusted in a Cox's regression model, the hazard ratio for lower limb overuse injury in the insole group was 1.3 (95% confidence intervals: 0.8-2.1) compared with the control group. Use of orthotic insoles was not associated with a decrease in lower limb overuse injuries. Our findings suggest that routine use of orthotic insoles does not prevent physical-stress-related lower limb injuries in healthy young male adults.

Anabolic-androgenic steroid use among young Finnish males.

The aim of the present study was to describe the lifetime occurrence and associated factors of anabolic-androgenic steroids (AAS) among young Finnish males. Of the 10 829 male conscripts (median age 19), 10 396 (96%) answered a questionnaire during the first days of their conscription in the years 2001-2007. The main outcome was lifetime AAS use. We also studied associations between 13 socioeconomic, health, and health behavioral background variables and AAS use by logistic regression. Eighty-nine (0.9%) respondents reported having used AAS. In addition, 26 (0.3%) respondents reported that they would use AAS if they could obtain them. In multivariate analysis, which included all significant variables and age, the strongest associated factors were weight training at fitness centers more than three times a week [odds ratio (OR) 11.8; 95% confidence interval (CI): 7.1-19.6], low educational status (OR 3.7; 95% CI: 2.0-7.0), and weekly drunkenness as drinking style (OR 2.4; 95% CI: 1.4-4.5). Sports other than weight training were not associated with AAS in our sample. The use of AAS is relatively uncommon among Finnish males. It is strongly associated with weight training at fitness centers but also with lower educational status and a drunkenness-oriented lifestyle. Prevention should be targeted at those males participating in weight training.

Cervical hip fracture in a Finnish population: incidence and mortality.

BACKGROUND AND AIMS: Our aim was to describe the incidence of cervical hip fractures and to describe the relationships between selected background variables and mortality at 30 days, 6 months, and 3 years postoperatively. MATERIAL AND METHODS: The basic material consisted of population-based data set of patients aged 65 years or older who had sustained a hip fracture and were treated operatively between 1999 and 2000. Out of these, we identified 266 consecutive patients with cervical hip fracture. RESULTS: The age-adjusted incidence of cervical hip fractures in women was 1.3-fold compared to men. In age-adjusted analysis, occurrence of chronic lung disease, cardiovascular disease or 2-5 comorbidities, male gender, the need for 2-person mobility assistance, and poor ambulation postoperatively were associated with excess mortality at least at one evaluation point. CONCLUSIONS: Only chronic lung disease and male gender were independent predictors of increased mortality at each follow-up assessment in multivariate analysis.

Can elevated serum TRACP-5b levels predict stress fractures? A cohort study.

BACKGROUND AND AIMS: Stress fracture is a common overuse injury in athletes and military conscripts. The reliable diagnosis of stress fractures is often difficult, however, because it is usually based solely on radiographic findings. Biochemical markers of bone resorption reflect bone degradation and may also reflect the rate of bone loss. The aim of the study was to examine whether elevated serum tartrate-resistant acid phosphatase isoform 5b (TRACP-5b) levels reflect enhanced bone remodeling and predict the occurrence of stress fractures in military conscripts. MATERIAL AND METHODS: Randomly selected military conscripts [mean age, 19.8 (range 18-28) years; n = 820] were followed for 3 months. Baseline blood samples were drawn upon arrival to the service. Four subsequent samples were obtained from subjects that developed stress fractures and one sample each was obtained from two asymptomatic control subjects for each fracture case. RESULTS: Plain radiography was used to diagnose stress fractures in 20 of the 820 conscripts (2.4%). Follow-up data were available for 14 subjects with 21 stress fractures and 28 control subjects. Subjects with proportionally increasing serum TRACP-5b levels had an 8-fold greater probability of stress fracture than controls. No statistically significant difference was detected. CONCLUSIONS: Although assessing serum TRACP-5b levels appears to be a promising method to predict bone stress injuries, the present study failed to give a conclusive statement of its usefulness as a diagnostic tool.

DEXA body composition changes among 140 conscripts.

The aim of the study was to determine changes in body composition and physical fitness during military service. A prospective cohort study of 140 healthy male conscripts was conducted. We examined subject characteristics, aerobic performance and muscle strength, and assessed body composition using dual-energy X-ray absorptiometry (DEXA) three times. Conscripts' mean baseline weight (79.5 kg) decreased by 2 kg during the first 3 months, but increased by 0.9 kg during the second 3-month period (p<0.001). Fat mass measured by DEXA decreased by 3.2 kg during the first but increased by 0.8 kg during the second 3-month period (p<0.001). Throughout the 6-month study, an increase was seen in distance of 12-min run test (from 2 380 m to 2 530 m; p<0.001), and muscle strength score (from 6.5 to 9.5 p<0.001). Finnish military training seems to have beneficial effects on physical fitness. However, considering the relatively modest changes in body fat and physical fitness seen in conscripts with average BMIs at baseline, design of diverse training programmes for the varying baseline BMI levels are warranted to improve the physical fitness results.

Lateral and Posterior Approaches in Hemiarthroplasty.

PURPOSE: Hemiarthroplasty is a common treatment for patient with a fragility displaced femoral neck fracture. We compared lateral and posterior approaches with respect to need for mobility aids, mobility level, living arrangements, pain, hip dislocation, and survival 12 months after hip fracture. METHODS: A total of 393 fragility femoral neck fracture patients aged 65 years or more who underwent hemiarthroplasty were observed for 12 months. Patient information was collected on admission, during hospitalization, and by telephone interview 1 year after the hip fracture. A total of 269 patients were included in the final analysis. RESULTS: At 1 year after hip fracture, more patients undergoing hemiarthroplasty with the posterior approach (22%) survived without mobility aids compared to those with the lateral approach (12%; p = 0.026). Multivariate logistic regression analysis revealed that the need for mobility aids 1 year after hip fracture was significantly predicted by the use of mobility aids before the fracture (odds ratio = 13.46, 95% confidence interval = 4.29-42.25), age ≥85 years (odds ratio = 3.85, 95% confidence interval = 1.09-13.44), male sex (odds ratio = 3.59, 95% confidence interval = 1.05-12.22), and lateral approach (odds ratio 2.73, 95% confidence interval 1.15-6.50). The posterior approach resulted in four (3.4%) dislocated hips, compared with none by the lateral approach. Survival, mobility level, pain in the operated hip, and living arrangements 1 year postoperatively were not significantly different between groups. CONCLUSION: Hemiarthroplasty using a lateral approach predisposed to the need for ambulatory aids 1 year after hip fracture. The posterior approach, however, predisposed to hip dislocation. Patient selection must be considered when deciding the appropriate surgical approach.

Elongated patellae at the final stage of Osgood-Schlatter disease: a radiographic study.

Aetiology of Osgood-Schlatter disease (OSD) is still unknown. Relative length of the patellar articular surface with the length of the patella, relative height of the tibial tubercle with the sagittal diameter of the tibia, Insall-Salvati, Blackburne-Peel, and Caton-Deschamps indexes, as well as Grelsamer-morphology type of the patella were measured from preoperative plain X-rays in 82 knees of 20-year-old males with OSD and in 87 knees of 20-year-old male controls with normal MRI findings of the knee. Seventy-eight of the OSD patients had separate ossicles. Their mean patellar morphology index was 1.44 and that of the controls was 1.28 (p<0.001), indicating significant lengthening of the patellar body among the OSD group. OSD patients had also significantly more often Grelsamer type II (elongated patellae) than the controls. Tibial tuberosity was significantly higher among OSD patients, but was not correlated with the lengthening of the patella. An increased patellar height among OSD patients was shown by the Blackburne-Peel and Caton-Deschamps indexes (p<0.001) and the Insall-Salvati index (p=0.018). OSD patients exhibit elongated patellae and patellar tendons which may result from long-standing tension of the extensor apparatus during growth spurt, when femoral growth exceeds that of the anterior structures of the knee.

Vitamin D fortification as public health policy: significant improvement in vitamin D status in young Finnish men.

BACKGROUND: Vitamin D insufficiency is common in northern countries during wintertime. In Finland, after the recommendation by the Ministry of Social Affairs and Health, vitamin D has been added to liquid milk products and margarines from February 2003. OBJECTIVE: We determined the effects of national policy on vitamin D fortification on vitamin D status among young Finnish men. DESIGN: A comparison before and after intervention with study population of 196 young Finnish men (18-28 years) was carried out. Serum 25-hydroxyvitamin D3 (25-OHD3) concentrations were determined with the OCTEIA enzymeimmunoassay by IDS (Immunodiagnostic Systems Limited, Bolden, UK) in January 2003 (n = 96) and in January 2004 (n = 100), nearly 1 year after national vitamin D fortification had started. RESULTS: The mean serum 25-OHD3 concentrations during the wintertime increased by 50% after implementation of the vitamin D fortification of dairy products. Correspondingly, the prevalence of vitamin D insufficiency (serum 25-OHD3 < 40 nmol/l) was decreased by 50% from 78% in January 2003 to 35% in January 2004. CONCLUSIONS: Our results demonstrate that national vitamin D fortification substantially improved the vitamin D status of young Finnish men. Still, a third remained vitamin D insufficient.

Long-term outcome of undisplaced fatigue fractures of the femoral neck in young male adults.

The incidence and long-term outcome of undisplaced fatigue fractures of the femoral neck treated conservatively were examined in Finnish military conscripts between 1970 and 1990. From 106 cases identified, 66 patients with 70 fractures were followed for a mean of 18.3 years (11 to 32). The original medical records and radiographs were studied and physical and radiological follow-up data analysed for evidence of risk factors for this injury. The development of avascular necrosis and osteoarthritis was determined from the follow-up radiographs and MR scans. The impact of new military instructions on the management of hip-related pain was assessed following their introduction in 1986. The preventive regimen (1986) improved awareness and increased the detected incidence from 13.2 per 100,000 service-years (1970 to 1986) to 53.2 per 100,000 (1987 to 1990). No patient developed displacement of the fracture or avascular necrosis of the femoral head, or suffered from adverse complications. No differences were found in MRI-measured hip joint spaces at final follow-up. The mean Harris Hip Score was 97 (70 to 100) and the Visual Analogue Scale 5.85 mm (0 to 44). Non-operative treatment, including avoidance of or reduced weight-bearing, gave favourable short- and long-term outcomes. Undisplaced fatigue fractures of the femoral neck neither predispose to avascular necrosis nor the subsequent development of osteoarthritis of the hip.

Fatal explosion injuries in Finland: a twenty-year nationwide survey.

BACKGROUND AND AIMS: Expanding violence may necessitate treatment of explosion victims, requiring a broadening of existing medical skills and knowlegde of injury mechanisms. The aim of the study was to assess the number, nature and injury pattern of fatal explosion incidents in Finland. MATERIAL AND METHODS: Retrospective analysis of explosion-related deaths from January 1985 to December 2004. Death certificates were obtained and reviewed. RESULTS: Over the 20-year period from 1985 to 2004, only 61 inviduals died in Finland as a result of unintentional or unspecified explosion related events. A homemade bomb assault for unknown motives killed seven people in a suburb in 2002. The incidence was 5.7 cases per 10,000,000 person-years. Suicides using explosives were slightly more common; on average 4 cases per year (6.7 cases per 10,000,000 person-years). A small increase in the fatality trend was noticeable during the last years of the study period. CONCLUSIONS: The incidence of fatal explosion injuries is a minor problem, but a small increase can be seen during the last few years. Victims of such injuries required only minimal hospital resources, because in most cases they died at the scene. Our results suggest that efforts to prevent fatalities related to explosives or corresponding devices, or to reduce their number, should focus on prevention of intentions.

Severe vascular gunshot injuries of the extremities: a ten-year nation-wide analysis from Finland.

BACKGROUND AND AIMS: Gunshot wounds affecting the main vessels of the extremities mostly threaten limb salvage. The purpose of this study was to analyse the nature and severity of civilian vascular gunshot injuries of the extremities using a nation-wide database. MATERIAL AND METHODS: Retrospective analysis of the Finnish Hospital Discharge Register, hospital records and death certificates over a 10-year period from January 1, 1990 to December 31, 1999. RESULTS: Thirty-two individuals with the mean age of 33 years (17-68) sustained 43 severe vascular injuries to the extremities caused by gunshots. The incidence was 6.0 (95% CI: 4.1-8.5) per 10,000,000 person-years and did not change significantly during the period. Four of the injured died. The most common anatomical locations of vascular injuries were the femoral artery (6 lesions), popliteal artery (6) and superficial femoral artery (5). Use of alcohol was detected in ten cases (32% of patients) and of illegal drugs in seven cases (22%). Five patients (18% of non-fatal injuries) required vascular re-operation caused by post-operative problems. Five amputations were performed as primary treatment. CONCLUSIONS: Severe vascular gunshot injuries of the extremities are not common in Finland. The need for primary amputation or vascular re-operations is noteworthy.

Fatigue injuries of the femur.

The purpose of this study was to describe the anatomical distribution and incidence of fatigue injuries of the femur in physically-active young adults, based upon MRI studies. During a period of 70 months, 1857 patients with exercise-induced pain in the femur underwent MRI of the pelvis, hips, femora, and/or knees. Of these, 170 patients had a total of 185 fatigue injuries, giving an incidence of 199 per 100 000 person-years. Bilateral injuries occurred in 9% of patients. The three most common sites affected were the femoral neck (50%), the condylar area (24%) and the proximal shaft (18%). A fatigue reaction was seen in 57%, and a fracture line in 22%. There was a statistical correlation between the severity of the fatigue injury and the duration of pain (p = 0.001). The location of the pain was normally at the site of the fatigue injury. Fatigue injuries of the femur appear to be relatively common in physically-active patients.

Tissue restoration after resorption of polyglycolide and poly-laevo-lactic acid screws.

Despite worldwide clinical use of bio-absorbable devices for internal fixation in orthopaedic surgery, the degradation behaviour and tissue replacement of these implants are not fully understood. In a long-term experimental study, we have determined the patterns of tissue restoration 36 and 54 months after implantation of polyglycolic acid and poly-laevo-lactic acid screws in the distal femur of the rabbit. After 36 months in the polyglycolic acid group the specimens showed no remaining polymer and loose connective tissue occupied 80% of the screw track. Tissue restoration remained poor at 54 months, the amounts of trabecular bone and haematopoietic elements being significantly lower than those in the intact control group. The amount of trabecular bone within the screw track at 54 months in the polyglycolic acid group was less than in the empty drill holes (p = 0.04). In the poly-laevo-lactic acid group, polymeric material was present in abundance after 54 months, occupying 60% of the cross-section of the core area of the screw track. When using absorbable internal fixation implants we should recognise that the degradation of the devices will probably not be accompanied by the restoration of normal trabecular bone.

Clinical biocompatibility of biodegradable orthopaedic implants for internal fixation: a review.

When the polymeric material reaches the final stages of its degradation process, biodegradable orthopaedic fixation devices elicit a local foreign-body reaction. In most cases, the symptoms of this tissue response are subclinical and pass unnoticed, but in some patients a clinically manifest inflammatory foreign-body reaction ensues. Mild clinical reactions consist of a painful erythematous papule, those of medium severity show a sinus discharging polymeric debris for up to 6 months, and in the patients affected by a severe reaction, extensive osteolytic lesions may develop at the implant tracks. The histopathologic picture is that of a non-specific foreign-body reaction. For implants made of polyglycolide, the average incidence of the manifest reactions is 5%. When slow-degrading polymers are used, the incidence is lower. The tissue responses to polyglycolide manifest themselves 11 weeks after surgery, on an average, whereas foreign-body reactions to devices made of poly-L-lactide can emerge as late as 4 or 5 yr after the original fracture fixation operation. A poorly vascularized bone section, use of a quinone dye as an additive in the polymer, and an implant geometry with large surface area each seems to be associated with an increased risk of the occurrence of a foreign-body reaction. Yet in majority of the patients affected, no known individual marker of high risk is present. Some recent laboratory experiments indicate that it may be possible to diminish the risk of an adverse tissue response by incorporating alkaline salts or antibodies to inflammatory mediators in the implants. The results of in vitro and animal experiments, however, cannot always be directly extrapolated to humans. Only large-scale long-term clinical research will ultimately show which physico-chemical characteristics of a biodegradable orthopaedic implant provide the optimal clinical biocompatibility.

In vivo monitoring of the degradation process of bioresorbable polymeric implants using magnetic resonance imaging.

The degradation of a bioresorbable poly(L-lactide) osteosynthesis plug after fixation of a transferred coracoid bone block using the Bristow-Latarjet procedure was examined by means of magnetic resonance (MR) imaging. There were 15 patients with a mean follow-up time of 38 months (range 34-42 months). The gross geometry of the biomaterial plug remained unaltered on the MR images. The bone marrow signal reached the implant surfaces in all cases, and no signs of liquid phase around the implant could be discerned. The implants themselves were visible as homogeneous low signal intensity (SI) black linear structures when compared to the surrounding bone, which had a much higher SI. The mean implant SI was 18.2 (s.d. +/- 6.6), that of the scapular bone 48.9 (s.d. +/- 14.3) and that of the background 4.3 (s.d. +/- 1.5). The SI of a newly manufactured intact implant was 5.7. Serial plain radiographs showed no decreased bone density or focal osteolytic lesions around the poly(L-lactide) expansion plug. The implant channel was discernible on most of the radiographs and a sclerotic rim was detected to outline the implant profile in some of the projections of plain radiographs at each follow-up examination. Computer tomography scans on five patients 3 years postoperatively also revealed a discernible implant channel outlined with a sclerotic rim. The radiographic appearance of the radiolucent implant channel did not change over the follow-up period. Summarizing the present findings, MR imaging seems to be able to visualize poly(L-lactide) implants within the bone. Actually, at present it is the only method available to study the degradation process of implants made of this polymer in humans. No signs of degradation of or of an osteolytic foreign-body reaction to poly(L-lactide) at the host tissue-implant interface could be observed within the follow-up times of this study.

Response of articular cartilage and subchondral bone to internal fixation devices made of poly-L-lactide: a histomorphometric and microradiographic study on rabbits.

To study the tissue response of articular cartilage and subchondral bone to biodegradable fixation devices, pins and rods made of poly-L-lactide with a fibers-in-matrix texture were implanted through the articular surface of the intercondylar portion of the distal rabbit femur. The initial raw material viscosity average molecular weight of the polymer was 660,000. One pin or screw was implanted per animal. The pins were cylindrical and measured 4.5 mm in transverse diameter. The screws had a core diameter of 3.2 mm and an outer diameter of 4.5 mm. At insertion, the implants were cut flush with the articular surface. After follow-up times of 36 and 48 weeks, the specimens were examined histomorphometrically and microradiographically. The intact contralateral femur served as a control for comparison. No signs of erosion or degradation of the polymer could be seen in the specimens. A brim of reparative tissue was formed at the entrance of the implant channel. The width of the reparative tissue from the tissue-implant boundary towards the center of the entrance hole varied greatly between the specimens, from 30 to 950 microm. In most specimens this bridging tissue consisted of undifferentiated mesenchymal tissue. Only two out of 24 specimens showed a near-normal metachromatic toluidine-blue staining of the matrix. Degenerative chondrocyte clustering occurred in the pre-existing cartilage within a 400 microm wide zone from the tissue-implant interface into the recipient tissues. Some new-bone formation was seen to envelop the implant in all specimens, but the fractional osteoid formation surface of the trabeculae showed a value significantly higher than that of the intact control side only in the screw-implanted 36-week specimens. Because of the long degradation time of poly-L-lactide, the restoration process of the articular cartilage was slow, and with regard to the quality and quantity of the reparative tissue, very variable. Large implants made of poly-L-lactide may not be suitable for insertion through intra-articular surfaces.

Shear strength of a distal rabbit femur during consolidation of an osteotomy fixed with a polylactide expansion plug.

The consolidation of a transverse transcondylar osteotomy of the distal rabbit femur, fixed with a self-reinforced polylactide expansion plug, was studied radiographically and mechanically. The peak shear force was assessed by stressing the osteotomy site to failure. The intact contralateral femur of the same rabbit served as a control. Fifteen rabbits were tested in groups of five animals with follow-up times of 6, 12 or 24 wk after fixation of the osteotomy. The absorbable plug, measuring 4.5 mm in diameter and 30 mm in length, had an expandable distal locking blade system. Thirteen osteotomies showed a radiographically solid bony union. The mean shear strength of the specimens was 3.5 MPa at 6 wk, 3.5 MPa at 12 wk and 4.3 MPa at 24 wk. The mean shear strength of the control distal femora was 3.6 MPa. In conclusion, the fixation properties of the newly developed absorbable expansion plug were deemed satisfactory in this experimental fracture model.

Comparison of the tissue response to absorbable self-reinforced polylactide screws and metallic screws in the fixation of cancellous bone osteotomies: an experimental study on the rabbit distal femur.

The availability of absorbable fracture-fixation devices for clinical use calls for better knowledge of the reaction of bone tissue to absorbable polyester implants as compared with similar metallic devices. To examine and compare the tissue response to biodegradable and metallic screws within cancellous bone, a transverse transcondylar osteotomy of the distal femur was fixed with absorbable self-reinforced polylevolactide screws in 35 rabbits and with stainless-steel screws in 35 rabbits. New bone formation and consolidation of the osteotomy were examined histologically, histomorphometrically, and microradiographically within standardized sample fields 1, 3, 6, 12, 24, 36, and 48 weeks postoperatively. The intact contralateral femur served as the control. A vigorous osteoconductive response to the polylevolactide screws was observed at 3 weeks postoperatively, and the osteoid surface fraction was significantly higher in all follow-ups than in the contralateral femora. In the femora with metallic screws, new bone formation was seen 3, 6, and 12 weeks postoperatively, but at 24, 36, and 48 weeks the osteoid surface fraction did not differ significantly from that of the intact control femora. The total bone area was significantly larger in the femora with self-reinforced polylevolactide screws than in the control bone 6-48 weeks postoperatively; in the femora with metallic screws, this was found only at 6 and 12 weeks. After 48 weeks, the femora fixed with metallic screws had statistically smaller total bone area than the intact control femora. Solid bone union was seen in 84% of the osteotomies in the self-reinforced polylevolactide group and in 76% of those in the metallic group after 3 weeks or more. No signs of degradation of the self-reinforced polyleuolactide implant and only a mild foreign-body reaction with no accumulations of inflammatory cells to either self-reinforced polylevolactide or metallic screws were observed during the follow-up period. Both types of screws seemed to induce an osteostimulatory response around their threads. This phenomenon was transient for metallic screws but lasted for at least 48 weeks for self-reinforced polylevolactide screws. The polylevolactide screw does not seem to cause osteopenia at the implantation site. The fixation properties of both self-reinforced polylevolactide screws and metallic screws appear to be sufficient for the fixation of small fragments of cancellous bone.

Magnetic resonance imaging during healing of surgically repaired Achilles tendon ruptures.

Twenty consecutive patients with 21 surgically repaired Achilles tendon ruptures were imaged with a 0.1-T magnet at 3 and 6 weeks, and at 3 and 6 months after surgery. Clinical follow-up examinations and functional tests were performed at the time of scanning. An intratendinous area of high-intensity signal was observed in 19 of the 21 surgically repaired Achilles tendons at 3 months after surgery on proton density- and T2-weighted images. The three patients with the largest lesions had clinically poor outcomes at 3 months, whereas those with smaller intratendinous lesions had normal recoveries. Furthermore, patients with an abnormal walk at 3 months (N = 5) had statistically larger intratendinous lesions than patients who could walk normally. In all patients the cross-sectional area of the rejoined Achilles tendon showed the largest increase after cast removal (between 6 weeks and 3 months after surgery). In all cases the largest tendon area was measured at 3 months after surgery. Magnetic resonance imaging provides a precise valuable tool to evaluate the postsurgical internal structure of the surgically repaired Achilles tendon.