Effect of local infiltration analgesia, peripheral nerve blocks, general and spinal anesthesia on early functional recovery and pain control in unicompartmental knee arthroplasty.

BACKGROUND: The aim of the study was to analyze the effect of local infiltration analgesia (LIA), peripheral nerve blocks, general and spinal anesthesia on early functional recovery and pain control in primary unicompartmental knee arthroplasty (UKA). METHODS: Between January 2016 until August 2016, 134 patients underwent primary UKA and were subdivided into four groups according to their concomitant pain and anesthetic procedure with catheter-based techniques of femoral and sciatic nerve block (group GA&FNB, n = 38) or epidural catheter (group SP&EPI, n = 20) in combination with general anesthesia or spinal anesthesia, respectively, and LIA combined with general anesthesia (group GA&LIA, n = 46) or spinal anesthesia (group SP&LIA, n = 30). Outcome parameters focused on the evaluation of pain (NRS scores), mobilization, muscle strength and range of motion up to 7 days postoperatively. The cumulative consumption of (rescue) pain medication was analyzed. RESULTS: The LIA groups revealed significantly lower (about 50%) mean NRS scores (at rest) compared to the catheter-based groups at the day of surgery. In the early postoperative period, the dose of hydromorphone as rescue pain medication was significantly lower (up to 68%) in patients with SP&EPI compared to all other groups. No significant differences could be detected with regard to grade of mobilization, muscle strength and range of motion. However, there seemed to be a trend towards improved mobilization and muscle strength with general anesthesia and LIA, whereof general anesthesia generally tended to ameliorate mobilization. CONCLUSIONS: Except for a significant lower NRS score at rest in the LIA groups at day of surgery, pain relief was comparable in all groups without clinically relevant differences, while the use of opioids was significantly lower in patients with SP&EPI. A clear clinically relevant benefit for LIA in UKA cannot be stated. However, LIA offers a safe and effective treatment option comparable to the well-established conventional procedures.

Effect of local infiltration analgesia, peripheral nerve blocks, general and spinal anesthesia on early functional recovery and pain control in total knee arthroplasty.

BACKGROUND: Postoperative pain control and enhanced mobilization, muscle strength and range of motion following total knee arthroplasty (TKA) are pivotal requisites to optimize rehabilitation and early recovery. The aim of the study was to analyze the effect of local infiltration analgesia (LIA), peripheral nerve blocks, general and spinal anesthesia on early functional recovery and pain control in primary total knee arthroplasty. METHODS: Between January 2016 until August 2016, 280 patients underwent primary TKA and were subdivided into four groups according to their concomitant pain and anesthetic procedure with catheter-based techniques of femoral and sciatic nerve block (group GA&FNB, n = 81) or epidural catheter (group SP&EPI, n = 51) in combination with general anesthesia or spinal anesthesia, respectively, and LIA combined with general anesthesia (group GA&LIA, n = 86) or spinal anesthesia (group SP&LIA, n = 61). Outcome parameters focused on the evaluation of pain (NRS scores), mobilization, muscle strength and range of motion up to 7 days postoperatively. The cumulative consumption of (rescue) pain medication was analyzed. RESULTS: Pain relief was similar in all groups, while the use of opioid medication was significantly lower (up to 58%) in combination with spinal anesthesia, especially in SP&EPI. The LIA groups, in contrast, revealed significant higher mobilization (up to 26%) and muscle strength (up to 20%) in the early postoperative period. No analgesic technique-related or surgery-related complications occurred within the first 7 days. Due to insufficient pain relief, 8.4% of the patients in the catheter-based groups and 12.2% in the LIA groups resulted in a change of the anesthetics pain management. CONCLUSIONS: The LIA technique offers a safe and effective treatment option concerning early functional recovery and pain control in TKA. Significant advantages were shown for mobilization and muscle strength in the early postoperative period while pain relief was comparable within the groups.

A model of cortical window healing in the rabbit.

A rabbit femur cortical window model was developed to study the time-dependent mechanical and radiographic changes with various treatments of surgically created windows. In the present experiment the time-dependent differences in torsional whole bone strength between femora treated with window replacement and those treated without replacement were evaluated. The 3.175 mm diameter windows were surgically created with a power trephine at the lateral femoral isthmus unilaterally, with the contralateral femur serving as a paired control. In one group of animals the window was reconstructed by replacement of the excised cortical plug while in the other group the window was left unreplaced. Each group was divided into three subgroups sacrificed at 3, 6, and 9 weeks postoperatively. Lateral radiographs were obtained immediately prior to sacrifice. After sacrifice bilateral femora were harvested and loaded to failure on a torsional testing apparatus to obtain values for ultimate torque, maximum angle of deformation, and energy capacity expressed as percent of paired control. Replacement resulted in significantly greater whole bone strength (P < .041), and strength increased significantly with time (P < .006). Radiographic appearance correlated significantly with both treatment and time, but not strength. The model was sensitive to both treatment-dependent and time-dependent effects, demonstrating potential for evaluation of other cortical window treatments.

Revision arthroplasty facilitated by ultrasonic tool cement removal. An evaluation of whole bone strength in a canine model.

Ultrasonic driven tools have been developed to facilitate the removal of bone cement during revision arthroplasty. The effect on whole bone strength of cement removal by ultrasonic tools was examined in a canine femur model. Paired, fresh-frozen canine femora were divided into two groups. In group A, one femur from each pair was subjected to cement extraction with ultrasonic tools. In group B, one femur from each pair was subjected to manual cement extraction. Contralateral femora from each pair served as controls to determine the strength of intact femora. Torsional fractures were produced using a servocontrolled hydraulic testing machine (Minneapolis Testing System, Minneapolis, MN). Maximum torque, maximum angle, and energy capacity to failure were determined. Results were recorded as a reduction in percent value of the tested specimen versus the contralateral control. When comparing femora with cement removal by ultrasonic tools to the contralateral control femur, there were no statistical differences in ultimate torque (P = .83), maximum angle (P = .89), and energy capacity (P = .74) by analysis of variance. In addition, there were no significant differences between the group with ultrasonic tool cement removal and the group with manual tool removal. The authors conclude that in this canine model, removal of cement with ultrasonically driven tools has no adverse effects on whole bone strength.

The effect of femoral stem geometry on interface motion in uncemented porous-coated total hip prostheses. Comparison of straight-stem and curved-stem designs.

We compared the magnitudes of motion between the prosthesis and bone during axial and torsional loading in seven matched pairs of fresh-frozen femora of cadavera in which an uncemented, collarless, isthmus-filling, straight-stem (Harris-Galante) prosthesis had been placed in one femur and an uncemented, collarless, proximal-filling, curved-stem (anatomic) prosthesis had been placed in the other femur. The comparison was performed in order to determine the effect of the geometry of the stem on the magnitude of motion. Single-limb-stance loads and combined axial and torsional loads were applied to the implanted femoral prostheses with the use of a jig that simulated acetabular and trochanteric loading. Extensometers were used to measure motion at the prosthesis-bone interface. The prostheses were then removed and were reinserted, with cement applied to the proximal porous coating to simulate ingrowth of bone. The single-limb-stance and combined axial and torsional loads were reapplied and the magnitude of motion was recorded again. No significant differences in the magnitudes of the motion were found between the femora in which the straight stem had been implanted and the femora in which the curved stem had been implanted, during either simulated single-limb-stance or low-intensity torsional loading. When large torsional moments (twenty-two newton-meters) were applied, significantly less motion occurred at the bone-prosthesis interface, both proximally (p = 0.019) and distally (p = 0.0013), in the femora with the curved-stem implant than in the femora with the straight-stem implant. When cement had been applied proximally, proximal and distal motion between the prosthesis and the femur was decreased during simulated single-limb-stance and during torsional loading in the femora with the straight stem and the femora with the curved stem.

The effect of extracorporeal shock wave lithotripsy on the prosthesis interface in cementless arthroplasty. Evaluation in a rabbit model.

The effect of extracorporeal shock wave lithotripsy on interfacial strength between prosthesis and bone in cementless arthroplasty was examined using a rabbit model. Paired femora, each implanted with fiber mesh porous coated titanium implants, were harvested from rabbits 15 weeks after implantation. In group I, one femur from each pair was exposed to lithotripsy treatment consisting of 2,000 shocks at 20 kV. In group II, one femur from each pair was exposed to 2,000 shocks at 26 kV. Contralateral femora from each pair served as controls in both groups. Mechanical pushout tests were conducted on the implants using a 1321 Instron testing machine at a constant rate of 1 mm/minute. Shock waves generated at 20 kV were found to have no significant decrease on either the prosthesis/bone interfacial strength or energy to failure of cementless implants. Shock waves generated at 26 kV produced a mean 17.45% decrease in the prosthesis/bone interfacial strength, which approached statistical significance (P = .062), and a 7.84% mean decrease in the energy to failure (P = .268). However, in four of the seven group II specimens, cortical fractures occurred. These findings suggest that lithotripsy will not aid in the removal of uncemented porous coated devices and lithotripsy inadvertently focused at an uncemented device will not disrupt significantly the prosthesis-bone interface.