Outcomes after shoulder arthroplasty revision with glenoid reconstruction and bone grafting

Purpose

Extensive glenoid bone loss after failed shoulder arthroplasty represents a challenge for revision arthroplasty. Treatment options vary widely and have been a source of controversy among experts.

Methods

Between 2004 and 2010, a total of 17 patients underwent glenoid reconstruction surgery using an autologous iliac crest bone graft and secondary revision arthroplasty due to extensive glenoid bone loss after failed previous total shoulder arthroplasty. The outcomes were assessed by means of clinical examination, Constant score, and bi-plane radiography as well as pre-, postoperative and follow-up CT.

Results

Before the revision surgery, the mean Constant score was 24 ± 17 and improved to 40 ± 13 after the glenoid rebuilding and revision arthroplasty. CT imaging revealed adequate glenoid bone stock restoration with no relevant graft resorption or loosening of the glenoid. The average postoperative antero-posterior diameter of the glenoid was 28 ± 3 mm which had decreased to 25 ± 3 mm at follow-up. The average postoperative version of the glenoid was 95.7° ± 6° and had decreased to 98.5° ± 4° at follow-up. Both the glenoid version and diameter had changed significantly (P < 0.001) comparing postoperative and follow-up CT-scans.

Conclusion

Glenoid reconstruction surgery using an iliac crest bone-block autograft prior to revision arthroplasty represents a valuable salvage procedure in cases of extensive glenoid bone loss after primary shoulder arthroplasty. Sufficient glenoid bone stock restoration is indispensable for reliable fixation of glenoid components and in turn a satisfactory clinical outcome.     

Repair of segmental long-bone defects by stem cell concentrate augmented scaffolds: a clinical and positron emission tomography - computed tomography analysis

Purpose

Treating segmental long-bone defects remains a major challenge. For defects >3 cm, segmental transport represents the gold standard, even though the method is time consuming and afflicted with several complications. The aim of this study was to evaluate healing of such defects after grafting an osteogenic scaffold previously seeded with stem cell concentrate.

Methods

We evaluated five patients with segmental long-bone defects (3–14 cm) treated with bone marrow aspirate concentrates (BMAC) seeded onto a bovine xenogenous scaffold. The healing process was monitored by X-rays and positron emission tomography–computed tomography (PET-CT) three months after surgery.

Results

Centrifugation led to a concentration of leukocytes by factor 8.1 ± 7.5. Full weight bearing was achieved 11.3 ± 5.0 weeks after surgery. PET analysis showed an increased influx of fluoride by factor 8.3 ± 6.4 compared with the contralateral side (p < 0.01). Bone density in the cortical area was 75 ± 16 % of the contralateral side (p < 0.03). The patient with the largest defect sustained an implant failure in the distal femur and finally accomplished therapy by segmental transport. He also had the lowest uptake of fluoride of the patient collective (2.2-fold increase).

Conclusion

Stem cell concentrates can be an alternative to segmental bone transport. Further studies are needed to compare this method with autologous bone grafting and segmental transport.     

Percutaneous Screw Fixation of Scaphoid Waist Fracture Non-Union Without Bone Grafting

The aim of the study was to evaluate results of volar percutaneous headless compression screw fixation without bone grafting in 21 patients with scaphoid waist nonunion fractures. The inclusion criteria in this series were scaphoid waist fracture nonunion with intact cartilaginous envelope, minimal fracture line at nonunion interface, no cyst or sclerosis, no avascular necrosis and normal scapholunate angle without humpback deformity. There were 17 male and 4 female patients with an average age of 23 years (range 16–45 years). All patients had radiographic examinations that included Posteroanterior, lateral, oblique and scaphoid views. Preoperative MRI to assess the cartilaginous shill and vascularity of scaphoid was done. CT scans were performed postoperatively to confirm scaphoid fracture healing. The average clinical follow-up was at 25 months (range 18–35) postoperatively. All fractures united successfully with no additional procedures. The average DASH score (disabilities of the arm, shoulder, and hand) at final follow-up was 8 (range 0–16). Percutaneous fixation for selected scaphoid nonunion can avoid the morbidity of an open approach and bone grafting.     

Evaluation of the Patient-Specific Functional Scale in hand fractures and dislocations

Background

Generic upper extremity disability questionnaires utilize standardized items. The Patient-Specific Functional Scale (PSFS) allows the patient to identify specific self-reported items. This study evaluated the validity of the PSFS to assess outcome in patients with hand fractures or dislocations.

Methods

Adults with hand fractures or dislocations, who completed hand therapy between January 2012 and January 2013, were eligible for inclusion. At the initial and final assessment, each patient was asked to complete the PSFS. Each patient identified three items that were difficult or they were unable to perform, and the degree of difficulty was ranked from 0 to 10 (able to perform at pre-injury level). We excluded patients with an incomplete PSFS. Statistical analyses evaluated the relationships between the PSFS and the independent variables.

Results

There were 63 patients (37 men, 26 women); 21 of the 63 patients underwent surgery for fracture fixation. The mean duration of hand therapy treatment was 2.2 ± 1.4 months. The mean PSFS scores were as follows: initial 3.2 ± 2.2; final 8.1 ± 2.2. There was a significant improvement in PSFS scores from initial to final assessment (p < 0.001) and a moderate correlation (r = 0.3, p = 0.02). There was no statistical difference in PSFS scores between men and women or surgery and no surgery.

Conclusions

In these patients with hand fractures or dislocations, the PSFS indicated significant improvement in function. Using items identified by the patient, the PSFS provides a valuable perspective of outcome and may be used in conjunction with generic disease-specific questionnaire for assessment of the upper extremity.     

Extra-articular dorsal closing-wedge osteotomy to treat late-stage Freiberg disease using polyblend sutures: technical tips and clinical results

Purpose

The purpose of this study was to evaluate the clinical outcomes regarding the dorsal wedge osteotomy fixed using a polyblend suture and describe the usefulness of this fixation method for the treatment of Freiberg disease.

Methods

The subjects consisted of 13 feet from 13 cases suffering from Freiberg disease that underwent extra-articular dorsal closing-wedge osteotomy using a polyblend suture. The average age was 31.7 (range 13–72) years. The average follow-up period was 17 (range 14–24) months. Regarding image findings, time to bone union and metatarsal shortening was reviewed. The investigation was carried out using the range of motion (ROM), visual analog scale (VAS), and Japanese Society of the Surgery of Foot lesser toe scale (JSSF score) in the MTP joint before surgery and at the latest follow-up.

Results

Calluses under the metatarsal head were not observed in any cases. The mean metatarsal shortening was 2.33 ± 2.07 mm at follow-up. The bone union required an average of 8.4 ± 0.8 weeks. The average ROM of dorsal flexion improved from 37.2 ± 5.3° before surgery to 73.6 ± 9.9° at latest follow-up (p < 0.0001). The average ROM of plantar flexion improved from 16.0 ± 10.1° before surgery to 19.5 ± 8.6° at latest follow-up (p = 0.35). The average VAS significantly improved from 75.3 ± 8.5 before surgery to 4.9 ± 4.2 at latest follow-up (p < 0.0001). The average JSSF score significantly improved from 67.3 ± 9.4 points before surgery to 98.8 ± 3.0 points at the latest follow-up (p < 0.0001).

Conclusion

Extra-articular dorsal closing-wedge osteotomy using a polyblend suture was carried out to treat Freiberg disease. The bone union was observed in all cases with improved clinical results. Fixation using a polyblend suture was considered to be useful.     

Cementation and interface analysis of early failure cases after hip-resurfacing arthroplasty

Purpose

The use of inappropriate cementation techniques has been suggested as an adverse factor for the long-term survival of hip-resurfacing arthroplasty. Inadequate initial fixation, thermal osteonecrosis and interface biological reactions are possible causes of failure. We analysed morphological changes associated with the cementation technique in a large collection of retrieved femoral components.

Methods

One hundred and fifty femoral components (mean time to failure of 8.3 months ± 11.0) obtained at revision surgery were analysed morphometrically and histopathologically. Cement mantle and penetration were quantified in six different regions of interest. Histopathological analysis of the bone–cement interface was performed on undecalcified processed bone tissue.

Results

The vast majority of the cases differed substantially from laboratory-based cement-penetration depth recommendations. Fifty-nine cases had a fibrous membrane at the cement–bone interface. This membrane was significantly thicker in cases with osteonecrosis compared to cases viable bone.

Conclusions

Our results demonstrate that most failures were cemented inappropriately. We suggest that poor cementation was an important adverse factor; however, the cause of the failures was obviously multifactorial. The thickness of the fibrous membrane at the cement–bone interface differed significantly between cases with osteonecrosis and specimens with viable bone tissue.     

External fixation versus volar locking plate for displaced intra-articular distal radius fractures: a prospective randomized comparative study of the functional outcomes

Background

The objective of the study was to compare the efficacy of external fixation and volar plating on the functional parameter of displaced intra-articular (Cooney’s type IV) distal end radius fractures using the Green and O’Brien scoring system.

Materials and methods

This prospective randomized study comprised 68 patients treated with external fixation and 42 patients treated with volar locking plates. The patients were followed up at 6 months and 1 year after surgery. The assessment of pain, range of motion, grip strength and activity were assessed at each follow-up visit and scored according to the Green and O’Brien scoring system.

Results

At 1 year after surgery, we observed that external fixation showed significantly better results than volar locking plates using the Green and O’Brien scores for range of motion (22.0 ± 4.77 vs 19.89 ± 5.05), grip strength (19.91 ± 5.4 vs 16.89 ± 4.4) and final outcome (87.36 ± 11.62 vs 81.55 ± 11.32). No difference was found in pain and activity between these two groups of patients. Patients aged <50 years treated with external fixation showed excellent results (final score (91.57 ± 9.01) at 1 year follow-up.

Conclusion

External fixation showed superiority over volar locked plating after 1 year of surgery.

Level of evidence

IV.     

Routine use of locking shaft screws is not necessary in volar plate fixation of distal radius fractures

Hypothesis

Volar locking plate fixation is a common treatment method for distal radius fractures. Recently, implants have been designed with an option to use locking screws in the shaft portion of the plate. While there is a high incidence of low bone mineral density in patients who sustain fragility fractures of the distal radius, the need for locking shaft screws is not well defined. Our hypothesis is that the routine use of locking screws in the shaft portion of volar plates is not required to maintain reduction or to prevent hardware failure.

Methods

A retrospective review was performed in all patients over age 50 years who underwent volar plate fixation using an implant with non-locking shaft screws for a distal radius fracture during a 2-year period. Patients were permitted to perform early range of motion exercises. Radiographs were examined and measurements were obtained to assess maintenance of reduction and incidence of hardware failure. Patients were followed at least until fracture healing. Patients were excluded from analysis if locking shaft screws were utilized or if follow-up was inadequate.

Results

Forty-one patients met the inclusion criteria. The average age was 62 years (range 50–79). There were 12 men and 29 women. The implant used incorporated 3.5-mm shaft screws in 26 patients and 2.4-mm shaft screws in 15 patients. All patients healed within acceptable radiographic parameters (mean volar tilt = 4.9°, mean radial inclination = 21.7°, mean radial height = 11.6 mm). There were not any instances of hardware failure.

Discussion

Distal radius fractures frequently occur in patients with low bone mineral density. Non-locking, bicortically placed shaft screws provide adequate stability to allow for early range of motion without loss of reduction or hardware failure. The routine use of locking screws in the shaft portion of volar plates does not appear justified.     

Reduction in Bone Volume Resection with a Newer Posterior Stabilized Total Knee Arthroplasty Design

Background

Posterior stabilized total knee arthroplasty requires an intercondylar notch to accommodate the cam housing that articulates with the tibial post to create femoral rollback required for deep flexion. The volume of bone resected for the intercondylar notch varies with implant design, and newer designs may accommodate high flexion with less bone resection.

Questions/Purposes

This study aims to analyze the bone volume and density resected from the intercondylar notch for three posterior stabilized implants from a single company: a Posterior Stabilized (PS) system, a Hi-Flex system (HF), and a rounded new box-reamer (RB) system and to further assess whether the newer RB with a cylindrical cutting tool would preserve more native bone.

Materials and Methods

Using a computer model, the PS, HF, and RB femoral components were digitally implanted into CT scans of 19 cadaver femurs. Nine cadavers were fit with a size 4 implant, six with size 3, and four with a size 2. The volume of intercondylar bone resected digitally for femoral preparation was measured. Bone density was measured by CT scans in Hounsfield units (HU). A paired t test was used to compare the mean volume of bone resected for each implant.

Results

For the size 4 femurs, the newer RB design removed 8% less intercondylar bone than the PS design (7,832 ± 501 vs. 8,547 ± 377 mm³, p < 0.001) and 28% less bone than the HF design (7,832 ± 501 vs. 10,897 ± 444 mm³, p < 0.001). The average HU for size 4 femurs for RB design was 427 ± 72 (PS = 399 ± 69, p < 0.001; HF = 379 ± 66, p < 0.001). For the size 3 femurs, the RB design removed 12% less intercondylar bone than the PS (6,664 ± 786 vs. 7,516 ± 648 mm³, p < 0.001) and 27% less bone than the HF (6,664 ± 786 vs. 9,078 ± 713 mm³, p < 0.001). HU for size 3 femurs for the RB design was 452 ± 70 (PS = 422 ± 53, p < 0.1; HF = 410 ± 59, p < 0.01). For the size 2 femurs, the RB design removed 5% less intercondylar bone than the PS (5,730 ± 552 vs. 6,009 ± 472 mm³, p < 0.01) and 22% less bone than the HF (5,730 ± 552 vs. 7,380 ± 532 mm³, p < 0.001). HU for size 2 femurs for the RB design was 430 ± 48 (PS = 408 ± 55, p < 0.01; HF = 385 ± 56, p < 0.01).

Conclusions

The newer RB design removes less bone from the intercondylar notch than the classic PS and HF designs in all sizes tested. The bone-conserving cuts incorporated into this newer implant design appear to preserve native bone without compromising design objectives.

Electronic supplementary material

The online version of this article (doi:10.1007/s11420-013-9340-1) contains supplementary material, which is available to authorized users.     

Malunited extra-articular distal radius fractures: corrective osteotomies using volar locking plate

Background

Multiple techniques for corrective osteotomy have been developed in recent years with the same aims: to improve the radiographic parameters and improve motion, pain and grip strength. Volar fixed-angle plates have added a new concept to the treatment of distal radius fractures thanks to the low morbidity of the surgical approach and the strength of the final construct, allowing early mobilization and return to function.

Materials and methods

Between 2005 and 2012, 20 patients with symptomatic dorsally malunited extra-articular fractures of the distal radius underwent corrective osteotomy using a volar locking plate without additional bone graft. At a mean follow-up of 50 months, all the patients were clinically and functionally evaluated.

Results

All measurements of pain, final range of motion and grip strength significantly improved compared with preoperative measurements. The mean preoperative DASH score reduced from 54 points preoperatively to 25 postoperatively. Based on the modified Mayo wrist score, we obtained 14 excellent and six good results. Palmar tilt improved from an average of 23° to 11°. Radial inclination improved from an average of 29° to 22°, and ulnar variance decreased from an average of 3.6 mm to 0.9 mm. There were two cases of transient median neuroapraxia that resolved before the 6-week follow-up appointment. No other major complications, including non-union and infection, were observed.

Conclusion

The volar approach and locking plate, without necessarily the use of bone grafting, proved to be an effective approach for addressing symptomatic and even severe deformities of the distal radius.

Type of study/level of evidence

Therapeutic IV     

Double tension band osteosynthesis in transverse supracondylar distal humerus fractures and nonunions

Purpose

The purpose of this study was to evaluate the objective and subjective results achieved after double tension band fixation in transverse extra-articular intracapsular supracondylar distal humerus fractures and nonunions in adults.

Methods

Nine patients presenting six fractures and three nonunions of the distal humerus, treated with double tension band wiring between 1998 and 2011, were retrospectively evaluated. Two fractures were type A2 and four type A3, and the nonunions were oligotrophic; all nine lesions had a supracondylar intracapsular transverse orientation, that passed through the olecranon fossa, in a direction parallel to the joint line, and they compromised both columns of the distal humerus. Patient’s age averaged 70 years (range, 56–82).

Results

Follow-up averaged 24.6 months (range, 12–53). All fractures and nonunions united; there were no infections, elbow stiffness or heterotopic bone formations. DASH score at final follow-up averaged 14.2 points (range, 4–22). The analog scale of pain averaged 1.1 points (range, 0–3). Elbow range of motion averaged 100° (range, 100–120°). Flexion averaged 123° (range, 115–130°) and elbow extension loss averaged 15.5° (range, 10–25°).

Conclusions

The results achieved with double tension band fixation in transverse extra-articular intracapsular supracondylar distal humerus fractures and nonunions are comparable to the results that can be expected when using other available fixation methods; this technique is faster, less demanding and cheaper, and surgeons should have it in mind when leading with these particular types of distal humerus fractures and nonunions.     

Medial Patellofemoral Ligament Reconstruction for Recurrent Patellar Instability Using a Gracilis Autograft without Bone Tunnel

Background

Several tendon graft and fixation methods have been introduced in medial patellofemoral ligament (MPFL) reconstruction for recurrent patellar dislocation. The purpose of this study was to evaluate the results of MPFL reconstruction using a gracilis autograft fixation without bone tunnel in patients with recurrent patellar instability.

Methods

Nine patients (four males and five females) diagnosed with recurrent patellar instability from July 2009 to January 2013 and had MPFL reconstruction using a gracilis autograft were included. The average age of the patients was 24.6 years (range, 13 to 48 years), and the average follow-up period was 19.3 months (range, 12 to 30 months). For every patient, femoral attachment was fixed using suture anchors securing the patella by suturing the periosteum and surrounding soft tissue. Clinical evaluation included the Kujala, Lysholm, and Tegner scores; in addition, patients were examined for any complication including recurrent dislocation. The congruence angle and patella alta were assessed radiologically before and after surgery.

Results

The Kujala score improved from an average of 42.7 ± 8.4 before surgery to 79.6 ± 13.6 (p = 0.008) at final follow-up; the Lysholm score improved from 45.8 ± 5.7 to 82.0 ± 10.5 (p = 0.008); and the Tegner score improved from 2.8 ± 0.8 to 5.6 ± 1.5 (p = 0.007). The Insall-Salvati ratio changed from 1.16 ± 0.1 (range, 0.94 to 1.35) before surgery to 1.14 ± 0.1 (range, 0.96 to 1.29; p = 0.233) at the final follow-up without significance. The congruence angle significantly improved from 26.5° ± 10.6° (range, 12° to 43°) before surgery to -4.0° ± 4.3° (range, -12° to 5°; p = 0.008) at final follow-up. Subluxation was observed in one patient and hemarthrosis occurred in another patient 2 years after surgery, but these patients were asymptomatic.

Conclusions

We achieved good results with a patellar fixation technique in MPFL reconstruction using a gracilis autograft employing soft tissue suturing in patients with recurrent patellar dislocation.     

Olecranon tip osteoarticular autograft transfer for irreparable coronoid process fracture: a biomechanical study

Background

We hypothesized that transfer of the olecranon tip for simulated type III coronoid fracture would restore posterior ulnohumeral translation to a level not different from that in the intact state.

Methods

The collateral ligaments were left intact in 12 fresh-frozen cadaveric elbows, and all other soft tissues were removed. The entire coronoid process was osteotomized flush with the ventral aspect of the ulna and was reconstructed using the tip of the olecranon process. Specimens were tested with an axial load of 100 N at 0.25 mm/s in 15° increments from 15 to 120° of flexion. Intact, osteotomized, and reconstructed posterior ulnohumeral displacement was measured.

Results

The bony reconstruction did not obstruct range of motion of the elbow. Intact translation (mean ± SD) ranged from 0.3 ± 0.1 to 1.1 ± 0.6 mm, and translation in the osteotomized state ranged from 1.3 ± 1.0 to 2.0 ± 1.0 mm. Resection of the coronoid resulted in a significant increase in posterior ulnar translation compared with intact at all flexion angles (p < 0.05) except at 75°. Reconstruction decreased translation versus the osteotomized state at all flexion angles, significantly at 60 and 120°. No significant difference in translation was found between reconstructed and intact states at five of eight positions tested.

Conclusions

In this biomechanical study of irreparable coronoid fracture, autograft olecranon tip transfer restored posterior elbow stability to a level not significantly different from the intact elbow in five of eight elbow positions tested.     

111Indium-oxine labelling for evaluating the homing process of autologous osteoblasts implanted percutaneously in atrophic nonunion fractures

Purpose

The aim of the study was to control the in vivo localisation of implanted cells in cell-based therapies. Labelling cells with ¹¹¹indium-oxine is one of the most interesting methods proposed. We evaluated this method in the setting of autologous osteoblast implantation in nonunion fractures.

Methods

An in vitro study of osteoblasts was conducted after ¹¹¹indium-oxine labelling. Radioactivity retention and viability, proliferation and the ability to produce alkaline phosphatase were evaluated in a seven-day culture. In vivo labelling of implanted osteoblastic cells was conducted during a therapeutic trial of atrophic nonunion fractures, with the leakage outside the nonunion site and local uptake evolution at four, 24 and 48 hour being studied.

Results

The mean labelling efficiency for osteoprogenitors was 78.8 ± 4.6 %. The intracellular retention was 89.4 ± 2.1 % at three hours and 67.3 ± 4.7 % at 18 hours. The viability assessed at three hours was 93.7 ± 0.6 %. After seven days of culture, morphology and alkaline phosphatase staining were similar for both labelled and unlabelled control cells, although the proliferation rate was decreased in the labelled cells. Some local intraosseous leakage was observed in four of 17 cases. All patients showed uptake at the injection site, with four having no other uptake. Four patients showed additional uptake in the bladder, liver and spleen, while 11 patients had additional uptake in the lungs in addition to the bladder, liver and spleen. The activity ratios (injection site/body) were 48 ± 28 % at four hours, 40 ± 25 % at 24 hours and 35 ± 25 % at 48 hours. After correcting for decay, the activity within the injection site was 82 ± 15 % at 24 hours and 69 ± 11 % at 48 hours compared with the activity measured at four hours. No relationship was found between uptake and radiological bone repair.

Conclusions

The ¹¹¹indium-oxine labelling appears to be a good method for monitoring the behaviour of the osteoblastic cells after their implantation in atrophic nonunion fractures.     

Mini-open versus extended open release for severe carpal tunnel syndrome

Background

This study aims to compare surgical outcomes of severe carpal tunnel syndrome (CTS) treated with mini-incision versus extensile release.

Methods

The method employed in this study was a retrospective review of patients with severe CTS, defined by electrophysiologic studies showing non-recordable distal sensory latency of the median nerve. Patients underwent either a mini-incision (2 cm) release of the transverse carpal ligament (group 1) or extensile release proximal to the wrist flexion crease (group 2). Exclusion criteria included prior carpal tunnel release, use of muscle flap, multiple concurrent procedures, or a prior diagnosis of peripheral neuropathy. Group 1 included 70 wrists (40 females, 30 males). Group 2 included 64 wrists (35 females, 29 males). Reported outcomes included pre- and post-operative grip strength as well as Boston Carpal Tunnel Questionnaires (BCTQ).

Results

Patients in group 1 had a 22.6 % increase in grip strength postoperatively (4.5 months ± 5.0), while patients in group 2 had a 59.3 % increase (10.0 months ± 6.9). BCTQ surveys from group 1 (n = 46) demonstrated a symptom severity score of 12.93 and functional status score of 9.39 at an average follow-up of 41.9 ± 10.6 months. Group 2 (n = 42) surveys demonstrated averages of 12.88 and 9.10 at 43.1 ± 11.6 months. One patient in the mini-incision cohort required revision surgery after 2 years, while no patient in the extended release cohort underwent revision.

Conclusion

No significant differences between the two procedures with regard to patient-rated symptom severity or functional status outcomes were found. Both techniques were demonstrated to be effective treatment options for severe CTS.     

Implanted passive engineering mechanism improves hand function after tendon transfer surgery: a cadaver-based study

Purpose

The purpose of this study was to investigate if a new tendon transfer surgical procedure that uses an implanted passive engineering mechanism for attaching multiple tendons to a single donor muscle in place of directly suturing the tendons to the muscle improves hand function in physical interaction tasks such as grasping.

Methods

The tendon transfer surgery for high median ulnar palsy was used as an exemplar, where all four flexor digitorum profundus (FDP) tendons are directly sutured to the extensor carpi radialis longus (ECRL) muscle to restore flexion. The new procedure used a passive hierarchical artificial pulley system to connect the muscle to the tendons. Both the suture-based and pulley-based procedures were conducted on N = 6 cadaver hands. The fingers’ ability to close around four objects when the ECRL tendon was pulled was tested. Post-surgery hand function was evaluated based on the actuation force required to create a grasp and the slip between the fingers and the object after the grasp was created.

Results

When compared with the suture-based procedure, the pulley-based procedure (i) reduced the actuation force required to close all four fingers around the object by 45 % and (ii) improved the fingers’ individual adaptation to the object’s shape during the grasping process and reduced slip by 52 % after object contact (2.99° ± 0.28° versus 6.22° ± 0.66°).

Conclusions

The cadaver study showed that the implanted engineering mechanism for attaching multiple tendons to one muscle significantly improved hand function in grasping tasks when compared with the current procedure.     

Transurethral cystolitholapaxy with the AH-1 stone removal system for the treatment of bladder stones of variable size

Background

The treatment of large volume bladder stones by current equipments continues to be a management problem in both developing and developed countries. AH-1 Stone Removal System (SRS) invented by us is primarily used to crush and retrieve bladder stones. This study evaluated the safety and efficiency of transurethral cystolitholapaxy with SRS for the treatment of bladder stones of variable size.

Methods

SRS, which was invented by Aihua Li in 2007, composed by endoscope, continuous-flow component, a jaw for stone handling and retrieving, lithotripsy tube, handle, inner sheath and outer sheath. 112 patients with bladder stones were performed by transurethral cystolitholapaxy with SRS since 2008. We compare the surgical outcome to bladder stones of variable size, and evaluate the surgical efficiency and safety.

Results

Characteristics of patients and stone removal time in variable size were evaluated. To patients with single stone, stone size was 1.35 ± 0.37 cm and the operating time was 5.50 ± 3.92 min in Group A. Stone size was 2.38 ± 0.32 cm and the operating time was 11.90 ± 9.91 min in Group B. Stone size was 3.30 ± 0.29 cm and the operating time was 21.92 ± 9.44 min in Group C. Stone size was 4.69 ± 0.86 cm and the operating time was 49.29 ± 30.47 min in Group D. The difference was statistically significant between the four groups. Among them, 74 (66.07%) patients accompanied with benign prostatic hyperplasia (BPH) were treated by transurethral resection of the prostate (TURP) simultaneously. Compared between the four groups, the difference of the TURP time was not statistically significant, P >0.05. No significant complication was found in the surgical procedure.

Conclusions

Transurethral cystolitholapaxy with SRS appears to be increased rapidity of the procedure with decreased morbidity. It is a safe and efficient surgical management to bladder stones. This endoscopic surgery best fits the ethics principle of no injury; meanwhile, the accompanied BPH could be effectively treated by TURP simultaneously.