High Recurrence Rates of Hyperextension After Total Knee Arthroplasty in Asian Patients With Preoperative Knee Hyperextension: A Prospective Observational Study

INTRODUCTION

Genu recurvatum is a well-known problem in total knee arthroplasty (TKA) in patients with and without neuromuscular disorders. Hyperextension of the knee joint does not reoccur significantly following adequate correction during TKA is the generally accepted notion. The literature regarding the reoccurrence of genu recurvatum in patients after TKA with preoperative genu recurvatum is scarce. The current study is an intermediate-range follow-up study to assess the pre- and postoperative sagittal plane profiles of Asian patients with genu recurvatum who underwent TKA. Changes in the sagittal profile in the immediate postoperative period were compared with the sagittal plane profile during the follow-up to the time of the final follow-up.

MATERIALS AND METHODS

This study was a prospective observational study of 21 patients (35 knees) with preoperative hyperextension of the affected knee who underwent total knee arthroplasty between July 2014 and September 2018, in our centre. The inclusion criteria were patients with primary osteoarthritis of the knee with recurvatum deformity ≥5° as measured preoperatively on a standing lateral radiograph. The exclusion criteria were neuropathic joints, post-traumatic arthritis, inflammatory arthritis, arthritis-associated neuromuscular disorders and revision procedures. The preoperative patients were divided into two groups: those with hyperextension of ≤10° and those with hyperextension of >10°. Radiographic measurements were done using the DICOM software (Kriens, Switzerland). The mean follow-up was 4.7 years (range: 3.6 to 7.6 years), and the minimum follow-up period was 3.6 years. No patients were lost to follow-up. All patients were evaluated clinically pre- and postoperatively using the Knee Society score. The knee range of movement and the coronal and sagittal profiles were recorded using standing radiographs. Statistical evaluation was done using the Chi-square test and the Wilcoxon signed-rank tests (SPSS version 17, Chicago, IL SPSS Inc, 2008).

RESULTS

Twenty-one patients (35 knees) with preoperative knee hyperextension underwent total knee arthroplasty with the mean age of patients being 59.38 years and the mean BMI of 32.28. The mean preoperative hyperextension was -10.1° (range: -5° to -26°). Early postoperative sagittal alignment (mean) was +4.5° (3° to 10°), and the mean sagittal alignment at final follow-up was -10.9° (-5° to -15°) (positive values indicate residual knee flexion, and negative values indicate hyperextension). There was no significant difference in the preoperative sagittal profiles of patients with BMI <30 and ≥30 (p=0.43). There was no statistically significant difference (p=0.19) between those with hyperextension of ≤10° and those with hyperextension of >10°.

CONCLUSION

 Till now, none of the patients have complained of symptoms related to hyperextension, although the rate of recurrence of hyperextension is high. Long-term follow-up is essential in patients with recurvatum deformity who have undergone TKA since delayed recurrence of hyperextension is possible despite adequate intraoperative correction of the deformity. Accurate preoperative prediction about the magnitude of postoperative deformity is not feasible. It is essential to counsel patients preoperatively that hyperextension may recur even after exercising sufficient care in the operative procedure to minimize its occurrence.

COVID-19 and orthopaedic surgery in a large trauma centre in India

Background:

We are in the midst of a pandemic caused by the novel SARS-Cov-2 virus. A large percentage of the patients are asymptomatic and hospitals around the world are struggling to restart routine services. We report the results of a universal testing protocol of all patients who underwent orthopaedic surgery in the month of July 2020 in a large orthopaedic speciality hospital in Bangalore, India.

Methods:

A retrospective study of all patients who underwent orthopaedic surgery in the month of July 2020 at a tertiary care orthopaedic speciality hospital in Bangalore, India. All patients underwent nasopharyngeal swab test before surgery. A questionnaire was used to assess the patient before the RT-PCR nasopharyngeal swab test. Data regarding imaging, investigations and follow up was recorded.

Results:

In the month of July 2020, 168 patients underwent routine nasopharyngeal RT-PCR swab test for COVID-19 prior to planned orthopaedic surgical procedure (Both trauma and elective cases). 16 of the RT-PCR tests were positive. However vascular cases and absolute emergencies were done without a RT-PCR test with PPE and all universal precautions. 11 patients underwent emergency surgery without a RT-PCR test. All 16 cases who were positive were asymptomatic. The asymptomatic positive rate was 9.52%. Of the 11 patients who underwent emergency surgery without a RT-PCR test, only one patient had a positive test post-operatively.

Conclusions:

Routine nasopharyngeal RT-PCR testing revealed a high rate of asymptomatic cases. If the RT-PCR test is positive, it is best to defer the case till the test returns negative. All precautions must be taken while performing emergency surgeries. Our algorithm in managing patients has proven to be effective and can be replicated with ease to continue operating and taking care of orthopaedic patients during this pandemic.

Revision Anterior Cruciate Ligament Reconstruction in the Nonathlete Population

BACKGROUND

There is considerable literature about revision anterior cruciate ligament (ACL) reconstruction in athletes vut there is little published evidence about the same in the nonathletes. The injury itself may remain underdiagnosed and untreated in nonsports persons. This study highlights the high incidence of ACL injury in the nonathletic patient cohort, revision rates, and the outcomes of revision ACL reconstruction.

MATERIALS AND METHODS

856 nonathletic patients who underwent primary ACL reconstruction were included in this retrospective study. Patients were asked on phone whether they had undergone revision surgery and whether they had symptoms severe enough to seek reintervention. Clinical assessment and preoperative and postoperative International Knee Documentation Committee (IKDC) and Lysholm scoring were used to followup patients who underwent revision intervention.

RESULTS

Clinically, symptomatic revision rate was 5.9% (51 out of 856 patients), and 33 out of these 856 patients (3.9%) underwent revision ACL reconstruction. The reasons for revision were rupture of the previous graft in 21 and laxity (incompetence) of the graft in 12 patients. The mean preoperative and postoperative IKDC scores were 44.1 and 69.8, respectively, and the improvement was statistically significant (P < 0.001). The IKDC score following revision ACL reconstruction was significantly better in those patients who underwent revision <1 year following the onset of recurrent symptoms (P = 0.015). Meniscal tears were present in 47.6%, and chondral injuries were seen in 33.3% of patients. The tibial tunnel positioning was abnormal in 70% of patients. Femoral tunnel positioning was aberrant in all the patients.

CONCLUSIONS

The revision rate of primary ACL reconstruction of 5.9% in nonathletes and revision ACL reconstruction rate of 3.9% are similar to the reported revision rates of 2.9%-5.8% in athletic patients. Similar to athletes, suboptimal tunnel placement is the major contributor to failure in nonathletes also.

Lateralization of Tibial Plateau Reference Point Improves Accuracy of Tibial Resection in Total Knee Arthroplasty in Patients with Proximal Tibia Vara

Background

The tibial cut referenced to the center of the intercondylar eminence often leads to varus malalignment in the presence of preexisting proximal tibia vara. The purpose of this study was to investigate the effect of lateralization of the lateral tibial plateau reference point (based on the amount of proximal tibia vara) on the postoperative coronal plane alignment.

Methods

In this prospective cohort study, 62 patients (95 knees) with osteoarthritis and proximal tibia vara underwent primary total knee arthroplasty using a lateral tibial plateau reference point for the extramedullary jig. The pre- and postoperative radiographs were obtained for measurement of mechanical axis deviation, degree of tibia vara, proximal lateral reference point of the tibial condyle, and coronal alignment of the femoral and tibial components. The distance between the tibial reference point and the center of the intercondylar eminence was measured intraoperatively.

Results

The mean tibia vara was 7.1° (standard deviation [SD], 2.3°). The mean lateral displacement of the reference point was 7 mm (SD, 2.2 mm). Postoperative tibiofemoral angle was 6° to 10° of valgus in 94% of cases. There was a strong correlation between the magnitude of tibia vara and the amount of lateralization of the tibial reference point (R² = 0.79, p < 0.001).

Conclusions

In total knee arthroplasty patients with proximal tibia vara, reasonable accuracy can be achieved with use of the extramedullary jig for tibial component alignment by lateralizing the proximal tibial reference point.

Lateralization of Femoral Entry Point to Improve the Coronal Alignment During Total Knee Arthroplasty in Patients With Bowed Femur

BACKGROUND

Intramedullary jigs are most often used for distal femoral bone cuts in total knee arthroplasty (TKA). However, the accuracy of bone cuts in the distal femur may be affected by the presence of diaphyseal deformities of the femur.

METHODS

Sixty-three patients (88 knees) with lateral bowing of the femur underwent primary TKA using a lateralized femoral entry point for intramedullary femoral guide. The following measurements were obtained on the preoperative and postoperative scanograms-mechanical axis deviation, degree of femoral bowing, femoral entry point from the intercondylar sulcus, distance from the center of the knee to the mechanical axis, and coronal alignment of femoral and tibial components.

RESULTS

In 48.8% of cases, the femoral entry point was 3-5 mm lateral to the intercondylar notch, in 44.4% of cases, it was 6-10 mm lateral to the notch, and in 6.8% of cases, it was 10-15 mm lateral to the intercondylar notch. Postoperatively the tibiofemoral angle was 6-10 degrees of valgus in 96% of cases. The postoperative mechanical axis was within 3 mm from the center of the knee in 80 of the 88 knees (90.9%). For every 1° increase in femoral bowing, the entry point was lateralized by an average of 1.04 mm.

CONCLUSION

The location of femoral entry point is important in TKA in patients with coronal plane deformity of the femur. In patients with lateral femoral bowing of 5° or more, a lateralized femoral entry point is useful in allowing straighter passage of long intramedullary femoral rod and this resulted in good mechanical axis alignment and femorotibial component alignment in over 90% of patients in our series.

PCL-retaining versus PCL-substituting TKR - Outcome assessment based on the "forgotten joint score"

BACKGROUND

Posterior cruciate ligament (PCL) retention or sacrifice figures prominently among the current controversies in total knee arthroplasty (TKA). Even though biomechanical advantages and disadvantages have been claimed for each type of TKA, clinical studies have not shown significant differences in the outcomes.

METHODS

In this retrospective study, the recently introduced "forgotten joint score" (FJS) was used to assess whether any differences exist between the two types of total knee replacement (TKR). FJ scores of 169 patients with PCL-retaining TKA and 178 patients with PCL sacrificing were obtained. The mean follow-up period was 3.5 years and the minimum follow-up period was 2.5 years.

RESULTS

Both groups showed high FJ scores indicating that majority of the patients were oblivious to the presence of the artificial joint during daily activities. There was no statistically significant difference between the mean FJ scores of the two groups. Scores of subsets based on gender, age and unilateral and bilateral TKR also did not show significant differences.

CONCLUSIONS

Since there are no clinically important differences between the two types of TKR, the choice of the TKA should be based on surgeon preferences and training and local conditions of the knee. Patient-reported outcomes appear to be similar regardless of the choice of TKA. Further prospective studies and validation of FJS outcomes with those of other questionnaires are essential to confirm the absence of differences between PCL retention and sacrifice.

Patellar tendon or hamstring graft anterior cruciate ligament reconstructions in patients aged above 50 years

BACKGROUND

The treatment of anterior cruciate ligament (ACL) injury consists of arthroscopic ACL reconstruction with patellar tendon or hamstring graft. Satisfactory results have been reported so far in the younger age group. Dilemma arises regarding the suitability of ACL reconstruction in patients aged 50 years and above. This retrospective analyses the outcome of ACL reconstruction in patients aged 50 years and above.

MATERIALS AND METHODS

55 patients aged 50 years and above presented to our institution with symptomatic ACL tear and were managed with arthroscopic reconstruction with patellar tendon/hamstring graft. 22 patients underwent ACL reconstruction with bone- patellar tendon-bone graft and the remaining 33 with a hamstring graft. Evaluation of functional outcome was performed using International Knee Documentation Committee (IKDC) and Lysholm scoring in the preoperative period, at the end of 1 year and at the final followup. Radiographic evaluation was performed using the Kellgren-Lawrence grading system.

RESULTS

The mean preoperative IKDC score was 39.7 ± 3.3. At the end of 1-year following the operation, the mean IKDC score was 73.6 ± 4.9 and at the final followup was 67.8 ± 7.7. The mean preoperative Lysholm score was 40.4 ± 10.3. At the end of 1-year following the intervention, the mean Lysholm score was 89.7 ± 2.1 and at final followup was 85.3 ± 2.5. Overall, 14 out of 42 patients who underwent radiographic assessment showed progression of osteoarthritis changes at the final followup after the intervention.

CONCLUSION

In our study, there was a statistically significant improvement in the IKDC and Lysholm scores following the intervention. There was a slight deterioration in the scores at the final followup but the overall rate of satisfaction was still high and most of the patients were able to do their routine chores and light exercises suitable for their age group. Around one-third of patients show progression of radiographic changes in the postoperative period and this requires long term evaluation.

Calcar femorale grafting in the hemiarthroplasty of the hip for unstable inter trochanteric fractures

BACKGROUND

The sliding screw-plate devices and cephalo-medullary nail devices have performed well in stable inter-trochanteric fractures in patients with reasonably good quality of bone. However, their suboptimal performance in comminuted fractures in the presence of osteoporotic bone has prompted many surgeons to consider bipolar hemiarthroplasty as the primary modality of management of comminuted inter-trochanteric fractures in elderly patients. However, long term stability of the hemiarthroplasty implant also may be compromised due to the presence of postero-medial bone loss at the area of the calcar.

MATERIALS AND METHODS

We have presented a simple and effective technique of calcar grafting by harvesting cortical bone strut from the neck of the fractured femur. A total of 34 patients with inter-trochanteric fractures of the femur were treated with calcar grafting. The mean age was 79.2 years. The graft was harvested from the calcar region of the head and neck fragment of the femur and wedged between the medial femoral cortex and medial edge of the prosthesis. The mean followup period was 54.5 months.

RESULTS

In 32 of 34 (94%) patients in our series, the calcar graft healed well without dislodgement. There was graft resorption in two patients associated with subsidence of the implant and loosening.

CONCLUSION

Calcar grafting using this technique provides stability to the implant in the presence of comminution and incorporates well in the majority of patients. Donor site morbidity of graft harvesting is also avoided.

Single locking compression plate fixation of extra-articular distal humeral fractures

Background

Earlier literature on fixation of distal third humeral fractures describes the use of elaborate modification of existing implants, custom-made implants and dual plating. These modifications have the disadvantages of limitations of hardware availability and cost as well as longer surgical exposure to accommodate the plates. The aim of this study was to assess the effectiveness of osteosynthesis of extra-articular diaphyseal fractures of the distal third of the humerus using a single 4.5-mm locking compression plate (LCP) with two-screw purchase in the distal fragment.

Materials and methods

We performed internal fixation of distal third extra-articular humeral fractures in 22 adult patients using 2–3 lag screws neutralized with a single 4.5-mm locking compression plate with only two screws in the distal fragment. The mean follow-up period was approximately 1.6 years.

Results

Fractures united in all 22 patients with minimal complications. The mean time to union of fracture was 13 weeks. The Mayo elbow score and the DASH scores were in the excellent and good category in all patients at final follow-up.

Conclusions

Our study showed that it is possible to obtain excellent outcomes in distal third fractures using only a single 4.5-mm LCP with two-screw (4-cortices) purchase in the distal fragment. The disadvantages inherent in the previous methods can be avoided with the use of the present technique. This technique obviates the need for the use of customized distal humeral implants and modified implants in most patients.

Level of evidence

Level IV.

PET/CT study of temporal variations in blood flow to the femoral head following low-energy fracture of the femoral neck

Earlier studies on femoral neck fractures have assessed the blood flow in either the pre- or postoperative period and information is lacking regarding changes in vascular flow to the femoral head after injury. Sixty-two adults with low-energy intracapsular femoral neck fractures were studied prospectively. Mean patient age was 57.2 years (range, 45-82 years). All patients underwent positron emission tomography/computed tomography (PET/CT) prior to surgical intervention and 6 weeks after internal fixation. Internal fixation was done using cannulated cancellous titanium screws and serial follow-up radiographs were obtained (at monthly intervals for the first 3 months followed by 3 monthly intervals between radiographs up to 2 years). On the preoperative PET/CT, 13 patients showed intact vascularity, 31 showed total loss of vascularity, and 18 showed partial loss of vascularity of the femoral head. The 6-week postoperative PET/CT scan showed recovery of blood supply in 23 of the 31 patients with total loss of vascularity and 15 of the 18 patients with partial loss of vascularity of the femoral head. Eleven of 62 patients had total or partial avascularity at the 6-week postoperative PET/CT scan and all 11 patients showed evidence of avascular necrosis on plain radiographs at the end of 2 years. The association between the vascular status of the femoral head at 6 weeks and avascular necrosis at the end of 2 years was statistically significant (P<.001). This study shows that the femoral head undergoes temporal variations in blood flow following femoral neck fracture. Decreased or absent vascularity is seen in approximately 75% of the fractures and 80% of the femoral heads with initial vascular compromise seem to regain blood flow within 6 weeks. Thus, prognostication about vascularity based on single-point preoperative imaging is difficult. The 6-week postoperative PET/CT scan seems to be reliable in predicting the future status of the femoral head. However, decision making regarding hemiarthroplasty or internal fixation at the time of injury may have to depend on factors other than the preoperative vascular status of the femoral head.

Isolated posterior instrumentation for selected cases of thoraco-lumbar spinal tuberculosis without anterior instrumentation and without anterior or posterior bone grafting

PURPOSE

The aim of this prospective study is the analysis of the clinical and radiological outcomes of active thoraco-lumbar spinal tuberculosis treated with isolated posterior instrumentation without any posterior bone grafting or anterior inter-body bone grafting or anterior instrumentation.

METHODS

The study was a prospective follow-up of 25 patients with active thoraco-lumbar spinal tuberculosis who underwent posterior spinal instrumentation with pedicle screws and rods. These patients had posterior stabilization of the involved segment of the spine without anterior or posterior bone grafting. The mean duration of follow-up was 3.3 years and the minimum duration of follow-up was 2 years.

RESULTS

The mean kyphotic angle improved from 32.4° pre-operatively to 7.2° in the early follow-up period. Following a minor loss of correction during follow-up, the mean kyphotic angle settled at 11.5° at the time of final follow-up. Inter-body bony fusion was noticed at the final follow-up in all patients despite the absence of anterior bone grafting or cages.

CONCLUSION

Posterior instrumented stabilization followed by chemotherapy seems to be adequate for obtaining satisfactory healing of the lesions. Anterior inter-body bony arthrodesis occurs despite the absence of anterior bone grafts or cages. Careful patient selection is critical for successful outcome with this technique.

A study on polyethylene stresses in mobile-bearing and fixed-bearing total knee arthroplasty (TKA) using explicit finite element analysis

Mobile-bearing total knee arthroplasty designs were thought to be associated with lesser stresses on the polyethylene (PE) insert as compared to fixed-bearing designs. The wear rate of the PE liner was felt to be less in the mobile-bearing knees due to the decrease in the stresses. However, a reevaluation of the biomechanics of the mobile-bearing design is necessary due to the recent clinical reports on the long-term outcome of mobile-bearing knees which have not demonstrated any significant benefit in terms of implant survival and polyethylene wear rate. In this explicit finite element analysis of mobile-bearing and fixed-bearing knee designs using LS-DYNA, no significant differences have been found in the maximal stresses in the superior (articulating) surface of the PE insert in mobile- and fixed-bearing designs. On the inferior surface of the PE insert, the peak stresses were nearly 30% higher in the mobile-bearing compared with the fixed-bearing design. Thus, contrary to earlier expectations, mobile-bearing designs may be associated with higher overall PE stresses and wear than the fixed-bearing designs. Further research is necessary to minimize the wear rate of the PE insert in mobile-bearing total knee arthroplasty.

Outcome of locking compression plates in humeral shaft nonunions

BACKGROUND

Nonunion of diaphyseal fractures of the humerus are frequently seen in clinical practice (incidence of up to 15% in certain studies) and osteosynthesis using dynamic compression plates, intra medullary nails and Ilizarov fixators have been reported previously. Locking compression plates (LCP) are useful in the presence of disuse osteoporosis, segmental bone loss and cortical defects that preclude strong fixation. We report a prospective followup study of the outcome of the use of LCP for humeral nonunion following failed internal fixation in which implants other than LCP had been used.

MATERIALS AND METHODS

Twenty four patients with nonunion of humeral shaft fractures following failed internal fixation were included in the study. The mean followup period was 3.4 years (range: 2.4 to 5.7 years) and the minimum followup period was 2 years. Mean age of the patients was 41.04 years (range: 24 to 57 years). All 24 patients underwent osteosynthesis using LCP and autologous bone grafting (cortico-cancellous iliac crest graft combined with or without fibular strut graft). Main outcome measurements included radiographic assessment of fracture union and pre and postoperative functional evaluation using the modified Constant and Murley scoring system.

RESULTS

23 out of 24 fractures united following osteosynthesis. Average time to union was 16 weeks (range: 10 to 28 weeks). Complications included delayed union (n = 2), transient radial nerve palsy (n = 2) and persistent nonunion (n = 1). Functional evaluation using the Constant and Murley score showed excellent results in 11, good in 10, fair in two and poor outcome in one patient.

CONCLUSIONS

Locking compression plating and cancellous bone grafting is a reliable option for achieving union in humeral diaphyseal nonunion with failed previous internal fixation and results in good functional outcome in patients with higher physiological demands.

Survival of dental implants in bisphosphonate users versus non-users: a systematic review

To investigate the literature regarding the survival rate of dental implants in bisphosphonate users as compared to non-users. An online search of literatures through MEDLINE-PUBMED (1950-March 2012), Cochrane Database of Systematic reviews, the Cochrane Central Register of Controlled Trials (CENTRAL) (1800-March 2012) and EMBASE (1966-March 2012) databases was performed. All the relevant publications were identified and full texts of these articles were obtained. After scrutinizing the relevant articles and their related references five articles that fulfilled the inclusion criteria were finalized. Only one study stated that dental implant failure was higher in patients under bisphosphonate therapy. The implant survival rates ranged between 95% and 100% in case of bisphosphonate users and 96.5% to 99.2% in non-users. Within the limitations of this review, it can be concluded that short term bisphosphonate therapy does not increase or decrease the survival rate of dental implants in bisphosphonate users as compared to non-users.

Modified Ponseti method of management of neonatal club feet

The aim of this study was to assess the outcome of a new protocol for the management of neonatal clubfeet that can be considered as a modification of the Ponseti method. The modifications consisted of performing the tenotomy of the Achilles tendon prior to the application of the first cast and using only one cast for a period of 3 weeks following tenotomy. We applied the modified method in 50 children (82 club feet) and assessed the degree of deformity using the Pirani and the Dimeglio scoring systems. The minimum follow-up period was 28 months (range: 24-32). The intermediate range follow-up results of this study showed that the modified Ponseti method was associated with a good outcome in 85% of cases of neonatal club feet with a Pirani score of 5 or less and a Dimeglio score of 15 or less. Persistently high Pirani or Dimeglio scores immediately after tenotomy and poor compliance with splintage were predictors of failure of the modified technique.

A theoretical comparison of the models of prevention of research misconduct

The current methods of dealing with research misconduct involve detection and rectification after the incident has already occurred. This method of monitoring scientific integrity exerts considerable negative effects on the concerned persons and is also wasteful of time and resources. Time has arrived for research administrators to focus seriously on prevention of misconduct. In this article, preventive models suggested earlier by Weed and Reason have been combined to arrive at six models of prevention. This is an effort to streamline the thinking regarding misconduct prevention, so that the advantages and disadvantages of each can be weighed and the method most appropriate for the institute chosen.

Use of antibiotic-loaded polymethyl methacrylate beads in the management of musculoskeletal sepsis--a retrospective study

OBJECTIVE

To assess the use of antibiotic-loaded polymethyl methacrylate beads in the management of chronic osteomyelitis of different aetiologies: infected osteosynthesis, infected open fractures, and haematogenous osteomyelitis.

METHODS

Records of 49 patients with chronic osteomyelitis who were treated at Department of Orthopaedics, Kasturba Medical College, from 1995 to 1999 were studied retrospectively. The diagnosis of chronic osteomyelitis was made on the basis of clinical and radiographic features. Of the 49 patients, 4 had haematogenous osteomyelitis, which later proved to be tuberculosis, and were thus excluded. Antibiotic-loaded acrylic beads were implanted in the remaining patients after thorough debridement. The implant was removed primarily in 16 patients with infected osteosynthesis, who then underwent decompression and sequestrectomy. All wounds were closed primarily. Peri-operative antibiotics were given for 7 days. Beads were removed at the end of 3 weeks followed by bone grafting in 26 patients. Patients were followed up for an average period of 3.7 years.

RESULTS

The infective organisms were sensitive to gentamycin in 26 cases and resistant in 19 cases; 14 cases were sensitive to cefuroxime, 11 to cloxacillin, 8 to ampicillin, and 5 to cotrimoxazole. Seven cases were resistant to all antibiotics tested. Of the 19 patients with gentamycin-resistant infection, only one had a poor result. No adverse systemic side-effects such as ototoxicity or nephrotoxicity were seen. Infection did not recur in 39 patients, but 6 patients had low-grade persistent infection at the last follow-up visit.

CONCLUSION

In chronic infections, especially those following osteosynthesis, antibiotic beads are a valuable adjuvant. The most valuable advantage is that the wound can be closed primarily, thereby reducing the incidence of nosocomial infections and requirement of nursing care.

Correlation between sagittal plane changes and adjacent segment degeneration following lumbar spine fusion

Adjacent segment degeneration following lumbar spine fusion remains a widely acknowledged problem, but there is insufficient knowledge regarding the factors that contribute to its occurrence. The aim of this study is to analyse the relationship between abnormal sagittal plane configuration of the lumbar spine and the development of adjacent segment degeneration. Eighty-three consecutive patients who underwent lumbar fusion for degenerative disc disease were reviewed retrospectively. Patients with spondylolytic spondylolisthesis and degenerative scoliosis were not included in this study. Mean follow-up period was 5 years. Results were analysed to determine the association between abnormal sagittal configuration and post operative adjacent segment degeneration. Thirty-one out of 83 patients (36.1%) showed radiographic evidence of adjacent segment degeneration. Patients with normal C7 plumb line and normal sacral inclination in the immediate post operative radiographs had the lowest incidence of adjacent level change compared with patients who had abnormality in one or both of these parameters. The difference was statistically significant (P<0.02). There was no statistically significant difference in the incidence of adjacent level degeneration between male and female patients; between posterior fusion alone and combined posterolateral and posterior interbody fusions; and between fusions extending down to the sacrum and fusions stopping short of the sacrum. It was concluded was that normality of sacral inclination is an important parameter for minimizing the incidence of adjacent level degeneration. Retrolisthesis was the most common type of adjacent segment change. Patients with post operative sagittal plane abnormalities should preferably be followed-up for at least 5 years to detect adjacent level changes.

Long-term follow-up of functional outcomes and radiographic changes at adjacent levels following lumbar spine fusion for degenerative disc disease

There are very few studies with more than 20 years' follow-up of lumbar spine fusions for disc degeneration. Currently, there is a lot of interest in the subject of degenerative changes above the level of fusion; this study is concerned with such changes in the very long term (30 years). Twenty-eight patients showing sound fusion on radiographs following posterior midline spinal fusion performed by a single surgeon between 1968 and 1970 were compared with an age- and gender-matched group of 28 patients who had undergone surgery for degenerative disc disease without fusion during the same period, by the same surgeon and using similar criteria for evaluation (Short Form 36 and Oswestry Disability Index; functional testing using self-paced walk and timed up-and-go; flexion and extension lateral radiographs of the lumbar spine). In this study, the incidence of radiographic changes at levels above the level of previous involvement was twice as high in the fusion group as in the non-fusion group. However, there was no statistically significant difference between the two groups in the outcomes measured using validated scales and functional testing. The study emphasises the importance of complete evaluation of these patients using validated outcome measurement instruments against the background of radiographic changes and subjective assessment of back pain. It also shows that radiographic changes do not necessarily mean functional impairment in all patients following lumbar spine fusion for degenerative disc disease.

Semen characteristics of the captive Indian leopard, Panthera pardus

Semen samples from 11 Indian leopards (Pantherapardus) from 3 different zoos in India were collected by electroejaculation. A computer-aided semen analyzer (CASA) was used for assessing the quality of the semen vis-à-vis sperm motility. The volume of the ejaculate, sperm density, and the number of motile and morphologically normal spermatozoa were found to be 1.57 +/- 1.26 mL, 55.78 million +/- 38.67 million per mL, 57.05% +/- 16.96% and 71.92% +/- 15.32%, respectively. Although the spermatology varied between individuals in the study, Box-Whisker-plot analysis suggested that the distribution was normal (P > .05). The ejaculated sperm were cryopreserved after diluting in test-yolk buffer. The post-thaw motility was 32.14% and did not differ at 30 or 60 days after cryopreservation. CASA indicated that the progressive velocity (VSL) of cryopreserved spermatozoa was decreased and, as a consequence, they moved more slowly than the neat (VSL 76.3 microm/sec in neat vs 53.8 microm/sec in cryopreserved spermatozoa) and the trajectories were less planar. However, both cryopreserved and neat spermatozoa penetrated the zona-free hamster oocyte with equal efficiency (79% neat vs 80% cryopreserved). The study also reports application of CASA for feline spermatozoa and provides information for the first time on the spermatology of the Indian leopard. This baseline data could be used in captive breeding programs. The results are compared and discussed with the available information on other felines.

Polymeric controlled drug-delivery systems: perspective issues and opportunities

Although, the drug-delivery system (DDS) concept is not new, great progress has been made recently in the treatment of a variety of diseases. Targeting delivery of drugs to the diseased lesions is one of the most important aspects of DDS. To convey a sufficient dose of drug to the lesion, suitable carriers of drugs are needed. Polymers, which swell and contract in response to external pH levels, are being explored. The research in this area is being carried out all over the world at a great pace. Not only that new developments are emerging in the existing technologies, but also various new technologies are being developed and tested. Consequently, a huge amount of new information is available, which should be compiled and presented in a comprehensive way to benefit large numbers of users in this area as well as to help active research workers in the field. The purpose of this review is to discuss some recent advances and future prospects in controlled drug-delivery technology. The article serves as a useful tool for the beginners as well as for the researchers actively involved in this fascinating area of applied polymer science.

"Fast-tracking" in patients undergoing coronary artery surgery with severely impaired left ventricular function

Cost containment and efficient resource utilization are motivating anaesthesiologists to early tracheal extubation of cardiac surgical patients. Fast track cardiac anaesthesia is both safe and cost-effective. We studied 45 patients with LVEF = 40% who underwent coronary revascularization and were put on the same fast track principle as those with normal ventricular function. Of these 31 patients (68.8%) had recent (<2 weeks) cardiac events requiring hospitalization. Acute myocardial infarction was documented in 8 patients (17.7%) and 23 (51.1%) had unstable angina. Congestive failure was present in 13 (28.9%) patients. Preoperative intravenous pharmacological support was needed in 17 (37.7%) patients, mechanical ventilation in 2 (4.5%) and IABP support in 1 (2.3%) patient. Anaesthetic management of these patients hinged on reduced usage of narcotics and muscle relaxants to facilitate early extubation. Operative strategy adopted was that of optimal revascularization. Beating heart surgery was adopted particularly in patients with low ejection fraction to avoid the attendant systemic and myocardial ill effects of cardiopulmonary bypass (CPB), especially in those who have had recent myocardial insults. Coronary surgery was performed on beating heart in 18 (40%) patients, while the other 27 (60%) patients were revascularised on CPB support. Of the 44 operative survivors, early extubation (<4 hours) was performed in 37 (84%) patients. Only 7 (16%) patients required ventilation for more than 24 hours. 3 out of these 7 patients were ventilated due to pulmonary reason and other 4 were ventilated since they were on IABP support. ICU stay was less than 24 hrs for 34/42 (80.9%) and hospital stay less than 6 days in 24/40 (60%). Fast tracking in cardiac surgery can be achieved with safety even in patients with impaired LV function.

Uncemented total hip arthroplasty in young patients with juvenile chronic arthritis

The hip joint is commonly affected in juvenile chronic arthritis (JCA) and involvement is usually bilateral. It is well established that the involvement of the hip in JCA is the most important reason that the patient will lose independence and mobility. The positive gains, both in terms of hip function and the overall functional capability, of the patients of JCA after hip replacement have been shown by several studies. There have been many reports regarding cemented total hip replacement in young patients with JCA. The short-term results have been excellent, but failure rates were considerably higher with further follow-up. To our knowledge there have been no other reports to date of the results of cementless arthroplasty of the hip in this condition. We reviewed the results of 25 primary uncemented total hip replacements (THR) in 16 patients with JCA. The mean postoperative follow-up time was 4.5 years (range 1-19 years). The clinical results were evaluated using the modified Harris hip score. The functional outcome was assessed by a scoring system described by Witt et al. The most significant long-term problem was acetabular loosening (12%) in our series.

Critical role of the sinuses of Valsalva in the durability of valved conduits

BACKGROUND AND AIMS OF THE STUDY

Most work in search of an ideal extracardiac valved conduit has assumed that the type of tissue used for construction is the determining factor for its behavior and durability. The excellent results of our study with a valved conduit incorporating sinuses of Valsalva and made of autologous pericardium showed that the design plays a crucial role in addition to the type of material.

MATERIALS AND METHODS

We report the experimental results of three different pericardial sinus bearing valved conduits made of 0.5% glutaraldehyde treated autologous pericardium (Group 1), dye mediated photooxidized bovine pericardium (Group 2), and glutaraldehyde treated bovine pericardium (Group 3) implanted in the right ventricular outflow tract of sheep. Groups 1, 2 and 3 had 11, 11 and four animals available for assessment out of 12, 18 and six implantations respectively. The valved conduits were explanted at varying intervals between one and 11 months. The conduit function was assessed with hemodynamic, echocardiographic and Doppler studies both at the time of implantation and sacrifice. The explanted conduit was studied macroscopically and subjected to histopathologic examination.

RESULTS

The hemodynamic and echocardiographic studies at implantation showed very satisfactory results in all three groups. At the time of sacrifice, Group 1 showed consistently good results. In a significant number of animals in Groups 2 and 3, one, two or even three cusps had become adherent to the conduit wall, resulting in severe regurgitation. The sinuses were well preserved in Group 1, while they were less prominent in Group 2 and least in Group 3. Histopathologically, the three groups basically showed the same feature, a process of fibrocellular proliferation resulting in thickening. In this study the adhesion of the cusps to the sinus wall was related to the degree of prominence of the sinuses of Valsalva, which in turn depended on the ability to shape the pericardium at the time of construction of the valved conduit.

CONCLUSIONS

This study stresses the importance of the sinuses in the behavior of the semilunar valve leaflets.

Autologous glutaraldehyde-treated pericardial valved conduit: an experimental study

Extracardiac conduits in the form of allografts and synthetic tubes containing heterograft valves have been used widely in the management of ventricular outflow abnormalities and for establishing ventriculoarterial continuity. These procedures are limited by long-term calcification as well as by formation of neointimal peel, necessitating reoperation. In an effort to continue the search for an alternative conduit, we designed and evaluated a valved sinus-bearing conduit fashioned out of autologous pericardium treated with glutaraldehyde. The construction of the conduit is described. The results of implantation of these conduits in 12 sheep showed no progression of gradients, fresh regurgitation, or evidence of wall or cusp calcification 9 months after implantation.

Characterization of four pupal wing cuticular protein genes of the silkmoth Antheraea polyphemus

Three different clones have been isolated from a genomic library of the silkmoth Antheraea polyphemus by employing a subtractive hybridization technique. The clones with inserts of 13-16 kb of DNA each, code for mRNAs expressed in the wing epidermis during JH induced second pupal cuticle deposition. While two of the clones code for a single mRNA each, the third one codes for two mRNAs. All the four mRNAs code for distinct polypeptides that can be precipitated with antibodies raised against pupal cuticular proteins. These genes are activated at the same period of pupal development and their transcripts follow similar patterns of accumulation. Although these genes are expressed in a tissue and time specific manner attesting to their pupal wing epidermal specificity, three of them are expressed in the adult wing epidermis also, but not at the larval stage. While DNAs from other silkmoths and insects hybridize to these genes, only one of the A. polyphemus genes hybridizes to RNA from second pupal wings of two other silkmoths tested.

Transcriptional regulation of calcium-activated neutral protease in cardiomyocytes of hypertensive rats

Increased enzymatic activity of calcium-activated neutral protease II (CANP II) has been reported previously in cardiac tissues of rats with 2 kidney, 1 clip Goldblatt hypertension (2K, 1C-HT); this was associated with elevated intracellular free Ca(++). Because it was suggested that increased levels of the enzyme were responsible for the enhanced activity, CANP II mRNA expression was assessed in cardiomyocytes isolated from 2K, 1C-HT rats and from a genetic model of hypertension, the spontaneously hypertensive rat (SHR). Utilizing a rabbit probe for the large subunit of CANP II (pLM 1006 cDNA), a 3.7 kilobase mRNA band was visualized in Northern blots of poly A+ RNA. Densitometric analysis of the blots revealed that there was a significant (p < 0.005) increase in the levels of CANP II large subunit mRNA in cardiomyocytes of 2K, 1C-HT rats when compared with controls. Interestingly, CANP II mRNA levels were comparable in cardiomyocytes of SHR and Wistar Kyoto (WKY) rats. Results of nuclear runoff transcription assays indicated that enhanced expression of CANP II mRNA in 2K, 1C-HT rat hearts was regulated at the transcriptional level. The data support specific CANP II gene activation in the hearts of renal hypertensive rats.