No difference in time-dependent improvement in functional outcome following closing wedge versus opening wedge high tibial osteotomy: a randomised controlled trial with two-year follow-up.

AIMS: The aim of this prospective randomised study was to compare the time course of clinical improvement during the first two years following a closing or opening wedge high tibial osteotomy (HTO). It was hypothesised that there would be no differences in clinical outcome between the two techniques. PATIENTS AND METHODS: Between 2007 and 2013, 70 consecutive patients were randomly allocated to undergo either a closing or opening wedge HTO. All patients had medial compartment osteoarthritis (OA), and were aged between 30 years and 60 years. They were evaluated by independent investigators pre-operatively and at three and six months, and one and two years post-operatively using the Knee Injury and Osteoarthritis Outcome Score (KOOS), the Oxford Knee Score (OKS), the Lysholm score, the Tegner activity score, the University of California, Los Angeles (UCLA) activity scale and range of movement (ROM). RESULTS: There were no significant differences at any time between the two techniques for any clinical outcome score (p > 0.05). The mean scores for all the systems, except UCLA and Tegner, significantly improved until six months post-operatively (p < 0.001). For some scores, the improvement continued until one and two years. CONCLUSION: This prospective randomised study suggests that there are no differences in the time course of the clinical improvement between the closing and opening wedge techniques for HTO during the first two post-operative years. Patients can expect continued improvement in physical function for between six months and one year after HTO regardless of the technique used. Cite this article: Bone Joint J 2017;99-B:1157-66.

Training increases the in vivo strength of the lower leg: an experimental study in the rat.

The effect of training on bone strength has been investigated in rats. After 7 weeks of training, fracture strength of the tibia in vivo during muscle contraction and after resection was assessed. A group of 30 male rats 11 weeks old were randomized to exercise on a treadmill, sedentary (ordinary caging), and inactivity (right-sided patellar tendonectomy) groups. The training group ran on a treadmill with a 10% inclination for 1 h per day. After 4 weeks the animals in all groups were anesthetized and the right lower legs loaded in three-point ventral bending until fracture during electrically induced muscle contraction. The contralateral tibiae were tested correspondingly after resection. Ultimate bending moment, energy absorption to failure, bending stiffness, and deflection were assessed for the in vivo and the resected tibiae. The body weight gain was 37% higher in the sedentary and 57% higher in the inactive animals than in the training group (P < 0.05), indicating a physiologic effect of the training. In the dissected tibiae there were no significant group differences in any of the mechanical parameters, indicating that neither training nor inactivity changed the structural capacity of the tibiae per se. In contrast, there were significant differences between the in vivo tibiae. Ultimate bending moment was 12% higher in the training group than in the sedentary and inactive groups (P = 0.03). Energy absorption in the training group was 11 and 12% higher (not significant) than in the sedentary and inactivity groups, respectively. Bending stiffness was 7 and 17% higher in the training group compared to sedentary and inactivity groups (P = 0.018).(ABSTRACT TRUNCATED AT 250 WORDS)

Muscle contraction increases the in vivo structural strength to the same degree in osteopenic and normal rat tibiae.

The increase in structural capacity due to muscle contraction in the lower leg was investigated in osteopenic and normal rats. Osteopenia was induced by ovariectomy combined with a low-calcium diet (0.01%). The control rats were sham operated and fed a diet containing 1.1% calcium. After 7 weeks the right lower leg of all animals were fractured in three-point ventral cantilever bending during muscle contraction induced by electrical stimulation of the ischiatic nerve. The left tibiae were resected and fractured as each animal's control. During muscle contraction in vivo, the ultimate bending moment, energy absorption, bending stiffness, and deflection were significantly lower in the osteopenic than in the sham-operated animals. However, the increase in mechanical parameters due to muscle contraction comparing the in vivo and resected tibiae in each animal were equally high in the osteopenic and sham-operated animals. Ultimate bending moment in the resected tibiae was 10% higher in the sham-operated animals compared with the ovariectomized, proving mechanically weaker tibiae in the osteopenic rats. In accordance with this, the medullary area of the osteopenic rats was 46% larger in the distal tibial diaphysis, and the ultimate stress the tibiae could withstand was 15% lower in the osteopenic compared with the sham-operated rats. The trabecular bone volume in the distal tibial metaphysis of the osteopenic rats was reduced by 70% compared with the sham operated. This study shows that muscle protection against fracture can be substantial in osteopenic tibia and that it is of the same magnitude as in rats with normal bone mass.

Muscle contraction increases the structural capacity of the lower leg: an in vivo study in the rat.

A model to study the contribution of muscle contraction to the structural capacity of the rat tibia was developed. The right lower leg was tested to failure in three-point ventral bending during electrically stimulated muscle contraction. The left lower leg was tested without stimulation, as a control. The mean ultimate bending moment for the stimulated legs was 0.603 Nm, compared with 0.492 Nm for the unstimulated legs (p < 0.001). The ultimate energy absorption was 0.313 and 0.188 J in the stimulated and unstimulated legs, respectively (p < 0.01). Fracture strength has been studied nearly exclusively in dissected bone stripped of all soft tissues. The present investigation suggests that studies of dissected bone are incomplete compared with the in vivo situation, as contraction of the muscles substantially increased the fracture strength of the lower leg in rats.

Hamstrings and gastrocnemius co-contraction protects the anterior cruciate ligament against failure: an in vivo study in the rat.

An anesthetized rat model was used to study the effects of muscle contraction on the ultimate tensile load and the energy absorption at failure of the anterior cruciate ligament. In both knees, the joint capsule and ligaments, except for the anterior cruciate ligament, were divided, and the menisci were removed with the aid of a stereomicroscope. The cruciate ligament of the right knee was tested in tension until failure by femorotibial distraction during contraction of the hamstrings and calf muscles induced by electrical stimulation of the ischiatic nerve. The cruciate ligament of the left knee, which was loaded to failure with nonstimulated (relaxed) muscles, served as the control. The mean ultimate tensile load during muscle contraction was 86 N compared with 53 N when tested with relaxed muscles (p < 0.001). The energy absorption at failure was 0.41 and 0.19 J during contraction and relaxation, respectively (p < 0.05). This study suggests that previous investigations evaluating the force and energy necessary to rupture the anterior cruciate ligament (with use of a femur-anterior cruciate ligament-tibia complex stripped of all soft tissues and without gastrocnemius-hamstring muscle contractions) are incomplete and probably not representative of the in vivo situation.

Interlocking intramedullary nailing in femoral shaft fractures. A report of forty-eight cases.

We treated forty-eight femoral-shaft fractures in forty-seven patients with the Grosse-Kempf interlocking intramedullary nail. Fifteen fractures were transverse or short oblique, ten were long oblique or spiral, and twenty-three were comminuted. Only twenty-four (50 per cent) of the fractures were located in the middle one-third of the shaft. The median time until full weight-bearing was thirty days (range, seven to 150 days). Radiographic consolidation was seen in all fractures at a median of sixteen weeks (range, nine to fifty-six weeks). The patients were followed for one to four years, and no infections developed. The results in thirty fractures were classified as excellent; in eight, as good; in seven, as fair; and in two, as poor. We have found the Grosse-Kempf method to be useful in treating patients with high-energy fractures, multiple injuries, open fractures, and osteoporosis. Since there is a risk of rotational and longitudinal instability with the dynamic method of interlocking nailing, we recommend that the static method be used whenever there is doubt about the stability of the fracture. We did not observe any delay in bone-healing when the static method was used.

Structural capacity of the knee to anterior cruciate ligament failure during quadriceps contraction. An in vivo study in the rat.

The effect of quadriceps contraction on the structural capacity of the knee joint loaded to anterior cruciate ligament (ACL) failure was studied in an in vivo rat model. In both knees of 20 rats the joint capsule and ligaments, except the ACL, were cut and the menisci resected by microsurgery. The rats were randomized to destructive testing of their ACLs either by femorotibial distraction or by anterior tibial translation at a displacement rate of 2.5 mm s-1 (60% s-1). The knee flexion during testing was 60 degrees. During loading of the right ACL, quadriceps contraction was induced by electrical stimulation of the femoral nerve. As control, the ACL of the left knee was loaded with relaxed quadriceps. The ultimate load for the knee to ACL failure when tested in tension by femorotibial distraction during quadriceps contraction was 140% higher than tested with the muscles relaxed (p = 0.0001). Energy absorption at failure during muscle contraction was 274% higher (p = 0.0001), and the linear stiffness increased by 59% (p = 0.0004). During testing by anterior tibial translation, neither linear stiffness nor ultimate load changed significantly, but the energy absorbed at failure was 46% (p = 0.02) higher during quadriceps contraction compared to testing with the quadriceps relaxed. These results showed that quadriceps contraction substantially increased the load carrying capacity of the rat knee subject to ACL failure when loaded by femorotibial distraction, but less when it was loaded by anterior tibial translation.

Lower extremity equipment-related injuries in alpine recreational skiers.

Lower extremity equipment-related injuries are the most significant injury group in alpine skiing. The lower extremity equipment-related injuries occurring at four Norwegian ski resorts were studied during the winter of 1985 to 1986. A total of 132 skiers with injuries were included (40% of all injured skiers) and compared with a randomly selected control population of 316 uninjured skiers. The most common lower extremity equipment-related injuries were knee sprains (56%) and lower leg fractures (14%), usually caused by no or late binding release. Significantly more lower extremity equipment-related injuries (33%) than other skiing injuries (19%) needed hospital admittance. Children below 10 years had a risk of lower leg fractures nine times that of skiers beyond 20 years. Beginners were six times more at risk for a lower extremity equipment-related injury than skiers of higher skiing abilities. The following factors were also associated with a significantly increased risk for a lower extremity equipment-related injury: less than three skiing seasons, no skiing instruction, and no self-testing of the bindings.

Quadriceps muscle contraction protects the anterior cruciate ligament during anterior tibial translation.

The proposed skiing injury mechanism that suggests a quadriceps muscle contraction can contribute to anterior cruciate ligament rupture was biomechanically investigated. The effect of quadriceps muscle force on a knee specimen loaded to anterior cruciate ligament failure during anterior tibial translation was studied in a human cadaveric model. In both knees from six donors, average age 41 years (range, 31 to 65), the joint capsule and ligaments, except the anterior cruciate ligament, were cut. The quadriceps tendon, patella, patellar tendon, and menisci were left intact. One knee from each pair was randomly selected to undergo destructive testing of the anterior cruciate ligament by anterior tibial translation at a displacement rate of 30 mm/sec with a simultaneously applied 889 N quadriceps muscle force. The knee flexion during testing was 30 degrees. As a control, the contralateral knee was loaded correspondingly, but only 5 N of quadriceps muscle force was applied. The ultimate load for the knee to anterior cruciate ligament failure when tested with 889 N quadriceps muscle force was 22% +/- 18% higher than that of knees tested with 5 N of force. The linear stiffness increased by 43% +/- 30%. These results did not support the speculation that a quadriceps muscle contraction contributes to anterior cruciate ligament failure. In this model, the quadriceps muscle force protected the anterior cruciate ligament from injury during anterior tibial translation.

The effect of knee bracing after anterior cruciate ligament reconstruction. A prospective, randomized study with two years' follow-up.

The purpose of this prospective, randomized, clinical trial was to evaluate the effect of knee bracing after anterior cruciate ligament reconstruction. Sixty patients were randomized into one of two groups: Patients in the braced group wore rehabilitative braces for 2 weeks, followed by functional braces for 10 weeks, and patients in the nonbraced group did not wear braces. Data were recorded preoperatively, and postoperatively after 6 weeks, 3 and 6 months, and 1 and 2 years. The following outcome measures were used: KT-1000 arthrometry, the Cincinnati knee score, goniometry to record range of motion, computed tomography to determine thigh atrophy, Cybex 6000 isokinetic testing to evaluate muscle strength, three functional knee tests, and a visual analog scale to evaluate pain. At all follow-up times there were no significant differences between the two groups with regard to knee joint laxity, range of motion, muscle strength, functional knee tests, or pain. However, the Cincinnati knee score showed that patients in the braced group had significantly improved knee function compared with patients in the nonbraced group at the 3-month follow-up, even though the braced group showed significantly increased thigh atrophy compared with the nonbraced group at 3 months.

Locked intramedullary nailing for displaced tibial shaft fractures.

We analysed the results of 93 tibial shaft fractures treated with the Grosse-Kempf locked nail. Twenty-six fractures were comminuted, 19 were open grade I to II, and 54 were located outside the middle third of the tibia. The deep infection rate was 3.2%. There were only two poor results. The use of this method is recommended and discussed.

Effect of trail design and grooming on the incidence of injuries at alpine ski areas.

OBJECTIVES: To identify the conditions at certain sites on slopes known as black spots for injury. METHOD: In the Hafjell and Voss alpine ski areas in Norway, 1410 skiing injuries were recorded from December 1990 through the 1996 season. In Hafjell, 183 of these injuries were plotted on an area map during the two first seasons. Similarly, in Voss, 214 injuries were plotted on an area map for two seasons. During the last three seasons in Hafjell, 835 ski injuries were related to 6712 snow grooming hours and 6,829,084 lift journeys. RESULTS: The mean injury rate was 2.2 injuries per 1000 skier days, and the mean injury severity score (ISS) was 3.1. Accumulations of injuries at three sites (black spots) were recorded on the Hafjell area map. These injuries represented 40% of all injuries in the alpine area (p<0.05). Seven injury accumulation sites were recorded on the alpine area map of Voss, representing 22% of the total injuries (p>0.05). Grooming of the slopes was rated poor for the 49% of injuries that occurred at the sites of injury concentration and significantly different (27%) from injuries that occurred at random in Hafjell. The corresponding values in Voss were 50% and 25% respectively. Grooming hours appeared to be inversely proportional to the number of injuries: R = -0.99 (p<0.02). The mean ISS declined significantly in Hafjell over the observation period (p<0.001). CONCLUSION: Inappropriate trail design and slope grooming seem to result in an accumulation of injuries at certain sites. Modification in construction and maintenance of the courses may reduce the number of injuries and mean ISS.

Fracture weakens ipsilateral long bones: mechanical and metabolic changes after femoral or tibial injury in rats.

We have studied the effect of tibial osteotomy on mechanical and metabolic properties of the femur, and the effects of femoral osteotomy or fracture on mechanical properties of the tibia in rats. In the bone ipsilateral to the trauma, there was a significant reduction of mechanical strength and stiffness, both in bending and torsion, compared with the contralateral side. The ipsilateral bone lost weight and the blood flow was increased. The mineral incorporation rate was not affected. This may be due in part to disuse of the traumatized limb, but the fracture itself may affect the other bones in the extremity.

Dynamic hip screw with trochanteric stabilizing plate in the treatment of unstable proximal femoral fractures: a comparative study with the Gamma nail and compression hip screw.

OBJECTIVE: To compare the results after operative treatment of unstable per- and subtrochanteric fractures with the Gamma nail, compression hip screw (CHS), or dynamic hip screw with a laterally mounted trochanteric stabilizing plate (DHS/TSP). DESIGN: Prospective. PATIENTS: One hundred seventy patients with unstable trochanteric femoral fractures surviving six months after operation. Eighty-five patients were randomized to treatment with the Gamma nail (n = 50, Gamma group) or the compression hip screw (n = 35, CHS group) and compared with a consecutive series of eighty-five patients operated with the dynamic hip screw with a laterally mounted trochanteric stabilizing plate (DHS/TSP group) MAIN OUTCOME MEASUREMENTS: Radiographs were analyzed for fracture classification, evaluation of fracture reduction, implant positioning, later fracture dislocation, and other complications. Pre- and postoperative functional status of the patients were recorded, with a minimum of six months follow-up. RESULTS: Eighteen percent of the patients in the Gamma group, 34 percent in the CHS group, and 9 percent in the DHS/TSP group suffered significant secondary fracture dislocation during the six months follow-up, leading to a varus malunion, lag screw cutout, or excessive lag screw sliding with medialization of the distal fracture fragment. Two patients (4.0 percent) in the Gamma group suffered an implant-related femoral fracture below the nail, and one had a deep infection. The reoperation rates were 8.0 percent in the Gamma group, 2.9 percent in the CHS group, and 5.9 percent in the DHS/TSP group. All but one fracture in the Gamma and CHS groups and two fractures in the DHS/TSP group healed within six months. Approximately three-fourths of the patients had returned to their preoperative walking ability after six months, with a trend toward better functional outcome in the DHS/TSP group. Use of a TSP reduced the secondary lag screw sliding as compared with the conventional CHS, without affecting fracture healing. CONCLUSION: The TSP may be an aid in the treatment of these difficult fractures because the problem with femoral shaft fractures using the Gamma nail is avoided and the medialization of the distal fracture fragment frequently associated with the CHS is prevented.

Assessment of functional tests after anterior cruciate ligament surgery.

Functional tests are often used to assess knee function after knee ligament injuries. However, the reliability and validity of these tests have not been sufficiently studied. The main purpose of this study was to examine six functional knee tests in order to establish the tests according to functional demands. The functional tests (vertical jump, figure-of-eight, stairs-running, triple jump, stairs hopple, and side jump tests) were evaluated on 35 patients after anterior cruciate ligament reconstruction (mean = 18 months postoperative). Evaluative variables were the Lysholm functional score, thigh atrophy, and knee instability. Factor analysis was used to identify knee tests based on the same basic variables in order to employ the most representative tests. The factor analysis disclosed two factors that reflected diverse functions. The first factor had significant correlation to the Lysholm score (daily life function) and was best represented by the figure-of-eight and stairs-running tests. The second factor was best correlated to the strength/stability function and was best represented by the triple jump test and the new stairs hopple test. Thus, the tests were categorized according to functional demands--daily life function and strength/stability function. The Lysholm functional score was inaccurate in identifying functional problems during strenuous activities.

Prospective study of changes in impairments and disabilities after anterior cruciate ligament reconstruction.

STUDY DESIGN: Single-group, repeated-measures prospective study. OBJECTIVES: To analyze changes in impairments and disabilities among patients with anterior cruciate ligament (ACL) reconstruction and to assess the relationships between the impairment and disability outcome measures from 3 months to 2 years following ACL reconstruction. BACKGROUND: Outcomes after ACL reconstruction can be categorized as impairments or disabilities. The relationship between impairments and disabilities may be crucial to understanding physical therapy interventions and predicting long-term outcome. METHODS AND MEASURES: Sixty patients who had undergone ACL reconstruction participated in the study. Impairment measures were range of motion, pain, knee-joint laxity, and muscle performance using isokinetic muscle tests. Disability measures were the Cincinnati knee score and lower limb performance using the triple-jump and stair-hop tests. Follow-up times were 3 and 6 months and 1 and 2 years after surgery. RESULTS: The Cincinnati knee score results show significant improvement 1 year after surgery (84.2 +/- 13.6) compared with 6 months (76.8 +/- 13.7) and 3 months (67.4 +/- 16.3) after surgery. Quadriceps total work (percentage of normal leg) significantly improved 2 years after surgery (92.6 +/- 14.1%) compared with 1 year after surgery (81.6 +/- 16.8%). Between 37 and 75% of the variability in the Cincinnati knee score could be explained by variation in the impairment variables, and quadriceps muscle performance and pain were the most significant predictors of disability. Extension deficit and pain at 3 months were significantly related to the Cincinnati knee score at the 2-year follow-up. CONCLUSIONS: Up to 2 years may be needed to regain normal quadriceps muscle performance following ACL reconstruction. Pain and quadriceps muscle performance explained most of the variability in the Cincinnati knee score.

[Experiences with interlocking nails in the femur. A retrospective analysis of 99 operated femur shaft fractures]. / Die Erfahrungen mit der Verriegelungsnagelung am Femur. Eine retrospektive Analyse 99 operierter Femurschaft-Frakturen.

In 95 patients 99 femoral fractures treated with an intramedullary locking nail were followed-up for median 22 months (12-60). 62 results were classified as excellent, 19 as good and 16 results as fair. A poor result was registered in 2 patients. We had 13 operation-related complications. Four of these complications required a new operation and one ended up with a poor end-result. Operative-technical complications do not necessarily need to impair the result if the surgeon is aware of them and knows how they are to be handled.

Injuries in military parachuting: a prospective study of 4499 jumps.

In this prospective study, the parachuting injuries which occurred during 2031 jumps in basic courses of free fall were compared with the injuries occurring during 2468 jumps for reserve paratroopers on training exercises. Fifty-eight injuries were recorded in 51 paratroopers. The ankle was most commonly affected, and 80 per cent of the injuries involved the lower extremity. Only 14 per cent of the injured troopers suffered severe injuries (fractures, knee ligament ruptures). The injury rate for paratroopers on basic courses (19.7 injuries per 1000 jumps) was significantly higher (P < 0.0001) than for those on training exercises (4.5 injuries per 1000 jumps). Similar observations were made for severe injuries (2.0 versus 1.2 injuries per 1000 jumps, respectively). The injury risk increased with age. Most of the injuries occurred on landing, and about 70 per cent were mainly caused by improper landing fall technique. The rate of serious parachuting injuries was low for Norwegian paratroopers.