Martti J. Kiuru

Treatment with and without Initial Stabilizing Surgery for Primary Traumatic Patellar Dislocation A Prospective Randomized Study

BACKGROUND There is no consensus about the management of acute primary traumatic patellar dislocation in young physically active adults. The objective of this study was to compare the clinical outcomes after treatment with and without initial stabilizing surgery for primary traumatic patellar dislocation in young adults. METHODS Forty young adults, thirty-seven men and three women with a median age of twenty years (range, nineteen to twenty-two years), who had an acute primary traumatic patellar dislocation were randomly allocated to be treated with initial surgical stabilization (eighteen patients, with each receiving one of two types of initial stabilizing procedures) or to be managed with an orthosis (twenty-two patients, including four who had osteochondral fragments removed arthroscopically). After a median of seven years, thirty-eight patients returned for a follow-up examination. Redislocations, subjective symptoms, and functional limitations were evaluated. Radiographs and magnetic resonance images were obtained at the time of randomization, and twenty-nine (76%) patients underwent magnetic resonance imaging at the time of final follow-up. RESULTS A hemarthrosis as well as injuries of the medial retinaculum and the medial patellofemoral ligament were found on magnetic resonance imaging in all patients at the time of randomization. During the follow-up period, six of the twenty-one nonoperatively treated patients and none of the seventeen patients treated with surgical stabilization had a redislocation (p = 0.02). Four nonoperatively treated patients and two patients treated with surgical stabilization reported painful patellar subluxation. The median Kujala scores were 91 points for the surgically treated patients and 90 points for the nonoperatively treated patients. Thirteen patients in the surgically treated group and fifteen in the nonoperatively treated group regained their former physical activity level. At the time of follow-up, a full-thickness patellofemoral articular cartilage lesion was detected on magnetic resonance imaging in eleven patients; the lesions were considered to be unrelated to the form of treatment. CONCLUSIONS In a study of young, mostly male adults with primary traumatic patellar dislocation, the rate of redislocation for those treated with surgical stabilization was significantly lower than the rate for those treated without surgical stabilization. However, no clear subjective benefits of initial stabilizing surgery were seen at the time of long-term follow-up.

Femoral Avulsion of the Medial Patellofemoral Ligament after Primary Traumatic Patellar Dislocation Predicts Subsequent Instability in Men: A Mean 7-Year Nonoperative Follow-Up Study

Background The clinical relevance of medial patellofemoral ligament (MPFL) injury location in primary patellar dislocation has not been studied. Hypothesis Prognosis after primary traumatic patellar dislocation may vary by MPFL injury location. Study Design Cohort study; Level of evidence, 3. Methods The initial magnetic resonance imaging (MRI) findings in 53 patients with identical nonoperative management were retrospectively analyzed for medial restraint injuries. The MPFL injury sites were classified as follows: femoral, midsubstance, and patellar. Magnetic resonance imaging was used to assess initial and control articular cartilage lesions in the patellofemoral joint. After a mean follow-up of 7 years, 42 patients were evaluated for redislocations, subjective symptoms, and functional limitations. Results Based on the initial MRIs, MPFL rupture was classified as femoral in 35 patients, midsubstance in 11, and patellar in 7. At follow-up, 15 patients reported an unstable patella (13 femoral, 1 patellar, 1 midsubstance; P =. 01) and 9 reported patellar redislocations (8 femoral, 1 midsubstance; P =. 05). The proportion of patients who regained their preinjury activity level was significantly smaller among those with femoral MPFL injury than among those with midsubstance or patellar MPFL injury (P =. 05). The median Kujala score was as follows: 90 for femoral, 91 for patellar, and 96 for midsubstance (P =. 76). Control MRI showed full-thickness patellofemoral cartilage lesions in 50% of the patients, unrelated to MPFL injury location. Conclusion An MPFL avulsion at the femoral attachment in primary traumatic patellar dislocations predicts subsequent patellar instability. The authors suggest that MPFL injury location be taken into account when planning treatment of primary traumatic patellar dislocation.

Factors associated with nonunion in conservatively-treated type-II fractures of the odontoid process

In type-II fractures of the odontoid process, the treatment is either conservative in a halo vest or primary surgical stabilisation. Since nonunion, requiring prolonged immobilisation or late surgery, is common in patients treated in a halo vest, the identification of those in whom this treatment is likely to fail is important. We reviewed the data of 69 patients with acute type-II fractures of the odontoid process treated in a halo vest. The mean follow-up was 12 months. Conservative treatment was successful, resulting in bony union in 32 (46%) patients. Anterior dislocation, gender and age were unrelated to nonunion. However, nonunion did correlate with a fracture gap (> 1 mm), posterior displacement (> 5 mm), delayed start of treatment (> 4 days) and posterior redisplacement (> 2 mm). We conclude that patients presenting with these risk factors are unlikely to achieve bony union by treatment in a halo vest. They deserve careful attention during the follow-up period and should also be considered as candidates for primary surgical stabilisation.

Lisfranc Fracture-dislocation in Patients with Multiple Trauma: Diagnosis with Multidetector Computed Tomography

Background: We assessed acute phase multidetector computed tomography (MDCT) findings of Lisfranc fracture-dislocations in patients with multiple trauma referred to a Level I trauma center over a 29-month period. Methods: Two hundred and eighty two patients (208 male and 74 female) between the ages of 13 and 89 (mean 42) years had, at the request of emergency room physicians, MDCT of the foot and ankle after acute injury. Results: A total of 21 Lisfranc fracture-dislocations were found in 19 (7%) patients. Two main injury mechanisms were established: falling from high places in 10 injuries (48%) and traffic accidents in five (24%). Primary radiographs were available in 17 (81%) feet, and four (24%) had false negative radiographic results when compared to MDCT. In all Lisfranc fracture-dislocations MDCT showed the joint anatomy and the extent of dislocation better than primary radiographs, and in six (46%) of 13 true positive primary radiographs, MDCT revealed additional occult fractures in the Lisfranc joint. Multidetector CT revealed additional occult fractures in other parts of the foot and ankle in six (35%) of 17 feet. Conclusions: Standard radiography remains a primary diagnostic modality in acute foot and ankle trauma. Multidetector CT with high-quality multiplanar reconstruction (MPR) is recommended as a complementary examination in high-energy injury in patients with multiple trauma or in patients in whom radiographic images are equivocal. This may reveal Lisfranc fracture-dislocations, show the extent of the fracture-dislocation, and reveal occult fractures in other parts of the foot and ankle.

Bone Stress Injuries in Asymptomatic Elite Recruits A Clinical and Magnetic Resonance Imaging Study

Background The occurrence and clinical significance of asymptomatic bone stress injuries is unknown. Hypothesis To evaluate by clinical and magnetic resonance imaging follow-up the occurrence of asymptomatic bone stress injuries, their clinical significance, and whether they all progress to stress fractures in subjects undergoing intensive physical training. Study Design Cohort study (prognosis); Level of evidence, 1. Methods Twenty-one male elite-unit military recruits voluntarily underwent clinical examination and magnetic resonance imaging before their intensive training period, 6 weeks into it, and on completion of the 5-month training program. Results Based on magnetic resonance imaging, a total of 75 bone stress injuries were detected. Only 40% (30/75) of the bone stress injuries had been symptomatic. Symptoms depended on location and magnetic resonance imaging grade of injury, with higher grades usually more symptomatic. Repeated clinical and magnetic resonance imaging assessment indicated that asymptomatic grade I bone stress injuries healed (21/25, 84%) or remained grade I and asymptomatic (3/25, 12%). The numbers of bone stress injuries, symptomatic cases, and recruits with bone stress injury increased toward the end of the intensive training period. Conclusions Asymptomatic grade I bone stress injuries seem common in subjects undergoing intensive physical training. Such bone stress injuries heal or remain asymptomatic grade I bone stress injuries even if intensive physical activity continues. They are therefore of no clinical significance. Only subjects who exhibit symptoms need undergo imaging studies. Subjects with an asymptomatic grade I bone stress injury may continue training but should be clinically monitored for symptoms.

Bone stress injuries

Bone stress injuries are due to cyclical overuse of the bone. They are relatively common in athletes and military recruits but also among otherwise healthy people who have recently started new or intensive physical activity. Diagnosis of bone stress injuries is based on the patients history of increased physical activity and on imaging findings. The general symptom of a bone stress injury is stress‐related pain. Bone stress injuries are difficult to diagnose based only on a clinical examination because the clinical symptoms may vary depending on the phase of the pathophysiological spectrum in the bone stress injury. Imaging studies are needed to ensure an early and exact diagnosis, because if the diagnosis is not delayed most bone stress injuries heal well without complications.

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.

Displaced femoral neck fatigue fractures in military recruits

BACKGROUND Displaced fatigue fractures of the femoral neck are uncommon, but they can lead to substantial patient morbidity. This study was performed to examine the incidence, long-term consequences, radiographic findings, risk factors, and complications associated with this fracture. METHODS Between 1975 and 1994, twenty-one military recruits sustained a displaced fatigue fracture of the femoral neck. Nineteen patients were followed for an average of eighteen years. Data regarding the population at risk, hospital records, initial and follow-up radiographs, and physical findings were analyzed. The impact of instructions from the Finnish Defense Forces, Department of Medical Services, provided in 1986 for prevention of femoral neck fatigue fractures was assessed. RESULTS At our institution, the incidence of displaced fatigue fractures of the femoral neck was 5.3/100,000 service years from 1975 to 1986, prior to the introduction of the prevention regimen in 1986, and it was 2.3/100,000 service years (95% confidence interval, 0.11 to 1.31) from 1987 to 1994. The rate of Garden type-IV fractures decreased from 3.8 to 0/100,000 service years (95% confidence interval, 0 to 0.66) between the first and second time-periods. The detection of nondisplaced symptomatic fatigue fractures of the femoral neck increased from 15.5 to 53.2/100,000 service years (95% confidence interval, 2.27 to 5.21) between the two time-periods. Eighteen of the nineteen patients had had prodromal symptoms prior to the fracture displacement. Following fracture treatment, six patients had delayed union or nonunion of the fracture. Osteonecrosis of the femoral head developed in six patients and was significantly associated (p = 0.001) with shortening of the femoral neck. Severe osteoarthritis developed in eight patients. CONCLUSIONS A displaced fatigue fracture of the femoral neck leads to long-term morbidity in a high percentage of patients. Most patients have prodromal symptoms, which provide an opportunity to prevent fracture displacement. Our results indicate that, in a military setting, an educational program can diminish the incidence of fatigue fracture displacement by increasing the awareness of these fractures and their prodromal symptoms and by facilitating diagnosis in the early stages before displacement occurs. LEVEL OF EVIDENCE Therapeutic Level III.

Comparison of Bioabsorbable Pins and Nails in the Fixation of Adult Osteochondritis Dissecans Fragments of the Knee An Outcome of 30 Knees

Background The optimal device for the fixation of osteochondritis dissecans fragments of the knee remains controversial and lacks long-term results. Purpose To review a group of young adults with osteochondritis dissecans of the knee treated with arthroscopic fixation of the fragment using bioabsorbable pins and nails and to examine the medium-term outcome of the fixation via magnetic resonance imaging and clinical evaluation. Study Design Cohort study; Level of evidence, 3. Methods Twenty-eight patients (30 knees) with osteochondritis dissecans of the knee were treated with arthroscopic fixation using bioabsorbable, self-reinforced poly-L-lactide pins and nails. All patients were young adult males with closed physes. The average follow-up time was 5.4 years (range, 3-12). At follow-up, magnetic resonance imaging studies were used to evaluate subchondral bone healing, and the outcome was evaluated by the Kujala score. Results The functional results were excellent or good for 73% of the patients in the nail group versus 35% in the pin group. The lesions treated were large, with an average size of 447 mm2, affecting the weightbearing area in the majority of the patients. On magnetic resonance imaging, incomplete bone consolidation was predominant in the pin group. Conclusions Arthroscopic fixation with bioabsorbable nails seems to be a suitable method of repair for osteochondritis dissecans of the adult knee and appears to be superior to arthroscopic fixation with bioabsorbable pins.

Bone Stress Injuries of the Ankle and Foot An 86-Month Magnetic Resonance Imaging–based Study of Physically Active Young Adults

Background No comprehensive studies of bone stress injuries in the ankle and foot based on magnetic resonance imaging findings have been published. Purpose Using magnetic resonance imaging findings to assess incidence, location, and type of bone stress injuries of the ankle and foot in military conscripts with ankle and/or foot pain. Study Design Case series; Level of evidence, 4. Methods All patients with ankle or foot pain, negative findings on plain radiography, and magnetic resonance images obtained of the ankle or foot were included in this 86-month study. Magnetic resonance images with bone stress injury findings were re-evaluated regarding location and injury type. Based on the number of conscripts within the hospital catchment area, the person-based incidence of bone stress injuries was calculated. Results One hundred thirty-one conscripts displayed 378 bone stress injuries in 142 ankles and feet imaged, the incidence being 126 per 100 000 person-years. This incidence represents the stress injuries not diagnosable with radiographs and requiring magnetic resonance images. Of injuries, 57.7% occurred in the tarsal and 35.7% in the metatarsal bones. Multiple bone stress injuries in 1 foot were found in 63% of the cases. The calcaneus and fifth metatarsal bone were usually affected alone. Injuries to the other bones of the foot were usually associated with at least 1 other stress injury. The talus and calcaneus were the most commonly affected single bones. High-grade bone stress injury (grade IV-V) with a fracture line on magnetic resonance images occurred in 12% (talus, calcaneus), and low-grade injury (grade I-III) presented only as edema in 88% of the cases. Conclusion Multiple, various-stage bone stress injuries of the ankle and foot may occur simultaneously in physically active young adults. When considering injuries that were missed by plain radiographs but detected by magnetic resonance imaging, the bones most often affected were the tarsal bones, of which the talus and calcaneus were the most prominent single bones and most common locations for higher grade (IV-V) bone stress injuries. With use of magnetic resonance imaging, early detection and grading of bone stress injuries are available, which enable early and appropriate injury management.