Efficacy and safety of porous hydroxyapatite/type 1 collagen composite implantation for bone regeneration: A randomized controlled study.

BACKGROUND: Porous hydroxyapatite/collagen composite (HAp/Col) is a bioresorbable bone substitute composed of nano-scale HAp and porcine type 1 collagen. In this study, the efficacy and safety were assessed in comparison to commercially available porous ß-tricalcium phosphate (ß-TCP). METHODS: Patients with bone defects caused by benign bone tumors, fractures, or harvesting of autografts were randomly allocated for implantation of porous HAp/Col (n = 63) or porous ß-TCP (n = 63). X-ray images were scored and used to evaluate the efficacy of the implantation until 24 weeks after surgery. Blood tests and observation of the surgical site were also performed to evaluate the safety of the implants. In total, 59 and 60 cases were analyzed in the porous HAp/Col and ß-TCP groups, respectively. RESULTS: At 18 and 24 weeks after surgery, the highest grade of bone regeneration was more frequent in the porous HAp/Col group than in the porous ß-TCP group (p = 0.0004 and 0.0254 respectively). Wilcoxon's rank sum test confirmed the superiority of porous HAp/Col from early time points onward (p = 0.0084, 4 w; p = 0.0037, 8 w; p = 0.0030, 12 w; p < 0.0001, 18 w; and p = 0.0316, 24 w). The incidence of adverse effects was higher in the porous HAp/Col group than in the ß-TCP group. However, no serious adverse events were reported and no cases needed to drop out of the clinical trial. CONCLUSIONS: The superiority of porous HAp/Col for bone regeneration in comparison to an established porous ß-TCP was confirmed. Although the incidence of side effects associated with the porous HAp/Col implant was higher than that in the ß-TCP group, no serious adverse events occurred that resulted in rejection of the implants.

Stress fracture of the bowed femoral shaft is another cause of atypical femoral fracture in elderly Japanese: a case series.

BACKGROUND: We have studied stress fractures of the bowed femoral shaft (SBFs) among elderly Japanese for over a decade. On the other hand, severely suppressed bone turnover (SSBT) after long-term bisphosphonates (BPs) use has been considered to be one of the causes of low-energy diaphyseal femoral fractures, often called atypical femoral fractures (AFFs). Some studies have shown that BPs use for more than 5 years is associated with an increased risk of AFFs. Here, we present a report of our SBF case series experienced in the past 15 years in order to examine whether bowing deformity should be considered among the causes of AFFs. METHODS: Subjects were 13 Japanese female patients with low-energy femoral shaft fractures. Mean age at injury was 77.0 years (range 67-88 years). All patients met the criteria of the AFFs' case definition. The first author treated 11 of the 13 patients over 8 years (2005-2012) based on the concept of SBFs. Regarding the regional characteristics of these patients, 10 were treated at 2 rural hospitals, and 3 were treated at 3 urban hospitals. Retrospectively, we assessed fracture type and location, existence of fracture on the contralateral side, bowing deformity, and duration of BPs use. RESULTS: All 13 cases were AO/OTA type 32-A. Incomplete or previous fracture on the contralateral side was noted in 10 cases. Obvious bowing deformity of the femoral shaft was noted in 12 cases. BPs were taken in 7 cases, only 3 of which involved BPs use for more than 5 years. CONCLUSIONS: We experienced 12 cases of low-energy femoral shaft fractures associated with bowing deformity. Six cases were not treated with BPs at all. Stress fractures associated with a femoral shaft bowing deformity do actually exist and should be recognized as another cause of AFFs.

Knee kinematics in anterior cruciate ligament-substituting arthroplasty with or without the posterior cruciate ligament.

Few studies have compared functional kinematics in knees using identical prostheses with or without the posterior cruciate ligament (PCL). This study contrasted in vivo knee kinematics with an anterior cruciate ligament-substituting arthroplasty with and without PCL retention. We hypothesized that knees without PCLs would exhibit less femoral posterior translation, and consequently less maximum knee flexion. Fifty-six knees were studied using dynamic radiography at least one year post-surgery, with twenty-seven knees retaining the PCL and twenty-nine knees having the PCL sacrificed. Consistent with our hypothesis, PCL-sacrificing knees showed more anterior femoral condylar positions. Contrary to our hypothesis, PCL-sacrificing knees demonstrated greater knee flexion during kneeling (122° versus 115°). Contracted PCLs in severely deformed knees likely were the cause of limited flexion in some retaining knees.

Matched comparison of kinematics in knees with mild and severe varus deformity using fixed- and mobile-bearing total knee arthroplasty.

BACKGROUND: We examined knee kinematics in three 16-knee cohorts with the same implant design to clarify the influence of bearing mobility and preoperative deformity on the kinematics of posterior-stabilized knee arthroplasty. Compared to knees with mild deformity and a fixed-bearing implant, we hypothesized that a matched group of knees with mobile-bearing prostheses would show greater tibial axial rotation. We hypothesized that knees with the same fixed-bearing implant, but severe preoperative deformity, would have less axial rotation. METHODS: A total of 58 knees in 48 patients were involved in this study from a consecutive single-surgeon total knee arthroplasty series. Sixteen knees received mobile-bearing prostheses, and a best-matched cohort of knees with fixed-bearing implants was selected. The 16 fixed-bearing knees with most severe preoperative deformity were selected as a third group. All knees were examined at least 1.5 years after surgery. Flexion, femoral external rotation, anteroposterior translation of both femoral condyles during squatting and deep knee flexion activities were evaluated using model-image registration techniques. FINDINGS: We found some statistically significant, but small differences among the three groups in dynamic and static knee kinematics. In squatting, total femoral rotation for knees with fixed- and mobile-bearing implants, and knees with fixed-bearing implants after severe preoperative varus deformity, was not significantly different. [7° (SD3°), 9° (SD3°), 8° (SD3°), respectively, P=0.08]. INTERPRETATION: Similar kinematic results for knees with different tibial bearing surfaces and preoperative deformities indicate a robust treatment with this posterior stabilized implant. However, knees did not exhibit normal femoral rotations or functional flexion ranges.

Is a minimally invasive approach superior to a conventional approach for total knee arthroplasty? Early outcome and 2- to 4-year follow-up.

BACKGROUND: Total knee arthroplasty (TKA) has been widely applied as an effective treatment for knee arthritis for several decades. More recently, minimally invasive surgery (MIS) has been developed for TKA. The purpose of this study was to clarify the difference in clinical results between MIS and conventional TKA. We hypothesized that knee function would recover earlier with MIS than with conventional TKA without major problems, and hence the middle-term outcome would be better with MIS TKA. METHODS: We retrospectively reviewed 48 primary TKAs performed using the same model of a posterior stabilized prosthesis by a single surgeon at our institution: 25 knees treated by a mini midvastus approach (MIS group) and 23 knees treated by a conventional midvastus approach (conventional group). Outcomes at the early stage and at the 2- to 4-year follow-up were evaluated and compared between the two groups. RESULTS: The average length of the skin incision was 10.9 cm in the MIS group and 17.1 cm in the conventional group. The duration of the surgery did not differ significantly between the two groups. Most of the components were correctly implanted in both groups, and no complications were observed. Active straight-leg raising could be achieved significantly earlier in the MIS group. Knee function at the 2- to 4-year follow-up did not significantly differ between the two groups. CONCLUSIONS: The early results and the wide indication encourage us to apply the MIS approach instead of the conventional technique. The limitation of this study was the small number of cases in the retrospective point of view. If the number were larger, perhaps other significant differences could be detected. Further investigations on a larger scale are required to solve this problem.

Stener-like lesions of collateral ligament ruptures of the metacarpophalangeal joint of the finger.

BACKGROUND: The Stener lesion of the ulnar collateral ligament of the metacarpophalangeal (MP) joint of the thumb is characterized by an interposition of the adductor aponeurosis between a distally avulsed ligament and its insertion into the base of the proximal phalanx. Stener-like lesions of the MP joint of the finger have been previously reported in only a few cases. METHODS: The authors experienced 38 cases of collateral ligament injuries of the MP joint of the finger. The two most frequently affected sites were the radial side of the little finger (21 cases) and the radial side of the ring finger (8 cases). We have previously reported some of these cases (22 cases), as well as clinical features and arthrographic findings. One Stener-like lesion in a collateral ligament injury of the MP joint of the ring finger was also reported earlier (Ishizuki, 1988). Additionally, Stener-like lesions were found postoperatively in six of eight cases surgically treated for collateral ligament injuries of the MP joint of the finger (little finger involvement in 5 cases and long finger involvement in 1 case). RESULTS: We experienced six cases of a Stener-like lesion of the MP joint of the finger. In five of these cases the distally avulsed collateral ligament was trapped by the opened window of the injured sagittal band. In the other case the ligament was avulsed at a proximal site, and the ruptured end was trapped by the sagittal band. All of the little fingers involving Stener-like lesions were abducted and unable to adduct. Therefore, an abducted little finger is an important sign of this lesion and is considered to warrant surgical treatment. Arthrograms provided information useful for identifying the lesions. In the radial three fingers, palpation of the tumor at the level of the collateral ligament may also be an important examining tool for identifying a displaced ruptured collateral ligament of the MP joint of the finger. CONCLUSION: We experienced six cases of Stener-like lesions of the MP joint of the finger. In all cases, the avulsed collateral ligament was trapped by the ruptured sagittal band. Surgical treatment was thought to be indicated in these cases. Therefore, it is important to avoid overlooking Stener-like lesions of the MP joint of the finger.

Prediction of primary reparability of massive tears of the rotator cuff on preoperative magnetic resonance imaging.

We studied magnetic resonance images of rotator cuff tears to determine whether it was possible to establish preoperatively the feasibility or infeasibility of primary repair. The study comprised 27 shoulders in 26 patients who underwent magnetic resonance imaging before surgery because of complete tears of the rotator cuff and who were treated with primary repair or by the patch graft technique because primary repair was not feasible. The length and width of each tear, the thickness of the supraspinatus muscle at the superior margin of the glenoid, and the presence or absence of a high signal intensity in the infraspinatus muscle were statistically analyzed. Primary repair was often not feasible when both the length and width of the tear exceeded 40 mm on a preoperative magnetic resonance image, when the supraspinatus muscle was thin at the superior margin of the glenoid, and when a high signal intensity was observed in the infraspinatus muscle.

Distal interphalangeal joint arthrodesis using a minimally invasive technique with the herbert screw.

The authors performed six joint arthrodeses of the distal interphalangeal joint in five patients without surface preparation of the joint using the Herbert screw. After the surgery, the joint was not splinted and the finger could be used in daily living activities, provided the patient did not attempt powerful pinching or gripping maneuvers with the affected finger. Although bony union of the joint was delayed, firm bone union was ultimately obtained in all joints. If it is acceptable to position the arthrodesis of the distal interphalangeal joint with 0 degrees of flexion, this technique can be considered very useful. Although the omission of joint surface treatment in this technique prolongs the period before bony union of the joint is attained, patients feel no inconvenience in using their fingers in daily living activities.

The polyester patch: a new technique to promote early motion exercises in extensor tendon transfers.

The polyester patch made from Bard-DeBakey Woven Fabric (C.R. Bard, Inc., Haeverhill, MA, U.S.A.) was used as the core of the interlacing suture. This new technique was applied mainly to extensor tendon transfers on the dorsum of the hand. The end-to-end interlacing suture technique with polyester patch was applied to seven patients with rupture of the extensor pollicis longus tendon, and the end-to-side transfer with a patch was applied to three patients with ruptures of the finger extensor tendon. Evaluation was performed using % total amount of motion. All seven patients who received the end-to-end interlacing suture with a patch were evaluated as good. Of the three patients who received the end-to-side transfer with a patch, two cases had a good result, and one case had a fair result. With this technique, active motion exercise may be started immediately after surgery without cast immobilization.

Antinociceptive effects of tizanidine, diazepam and eperisone in isolated spinal cord-tail preparations of newborn rat.

Antinociceptive effects of three centrally acting muscle relaxants, tizanidine, diazepam and eperisone, were studied using an isolated newborn rat spinal cord-tail preparation. Potentials were recorded from a lumbar ventral root (L3-L5) extracellularly using a suction electrode. Pinch stimulation applied to the tail elicited a depolarizing response in the ventral root lasting 15-30 sec, referred to as the tail-pinch potential. Electrical stimulation of the ipsilateral dorsal root of the same segment with a single shock induced depolarizing responses in the ventral root. The responses consisted of monosynaptic and polysynaptic reflexes with a fast time course, followed by a slow depolarizing response lasting about 20 sec. The latter slow response was designated the ipsilateral slow ventral root potential (VRP). Both the tail-pinch potential and the ipsilateral slow VRP were depressed by application to the spinal cord of tizanidine (2-3 microM), diazepam (2 microM) and eperisone (100-200 microM). The effect of tizanidine was reversed by alpha 2-adrenoreceptor antagonists, yohimbine and idazoxan, but not by an alpha 1-antagonist, prazosin. The effect of diazepam was reversed by the benzodiazepine antagonist, flumazenil.