ABSTRACT
PURPOSE: To compare adverse events, medical resource utilization, prescribing patterns, and revision surgery rates of patients with opioid-related disorders (ORDs) undergoing primary hip arthroscopy against a propensity-matched group with no opioid-related disorders (NORDs). METHODS: The TriNetX database was queried between January 2015 and December 2020 using International Classification of Diseases, 10th Revision and Current Procedural Terminology codes to identify patients undergoing primary hip arthroscopy between ages 18 and 70 years. The ORD cohort was propensity matched in a 1:1 ratio to NORD patients based on age, sex, alcohol-related disorders, heart disease, hypertension, metabolic disorders, anxiety disorders, major depressive disorder, diabetes mellitus, and antidepressant prescriptions. Postoperative rates of adverse events and medical resources were compared within 90 days of procedure, prescriptions were compared within 1 year, and revision surgery was compared within 2 years. RESULTS: A total of 809 ORD patients were propensity matched in a 1:1 ratio to NORD patients. Postoperative adverse events were similar between groups (P = .693). Rates of revision arthroscopy were also similar for both ORD (9.3%) and NORD (8.0%) cohorts (odds ratio [OR], 1.17; 95% confidence interval [CI], 0.83-1.66; P = .377). ORD patients received care from the emergency department, inpatient admission, outpatient visit, and physical therapy evaluations at higher rates. The ORD cohort received a greater amount of new opioid (OR, 2.66; 95% CI, 2.17-3.26; P < .0001) and antidepressant prescriptions (OR, 1.58; 95% CI, 1.26-1.97; P < .0001) compared to NORD patients within 1 year of surgery. CONCLUSIONS: ORD patients demonstrated similar rates of adverse events and revision surgery when compared to a propensity-matched group of NORD patients undergoing primary hip arthroscopy. However, ORD patients experienced increased rates of emergency department visits and hospitalizations and were prescribed higher rates of opioid and antidepressant prescriptions. LEVEL OF EVIDENCE: Level III, cohort study.
Subject(s)
Arthroscopy , Databases, Factual , Opioid-Related Disorders , Humans , Male , Female , Middle Aged , Adult , Aged , Adolescent , Young Adult , Reoperation/statistics & numerical data , Postoperative Complications/epidemiology , Hip Joint/surgery , United States , Propensity Score , Analgesics, Opioid/therapeutic use , Patient Acceptance of Health Care/statistics & numerical dataABSTRACT
The purpose of this study was to evaluate whether a minimally-invasive cubital tunnel release using lighted retractors could be performed safely and completely by residents with no prior training in this technique. Ten residents participated in the study. Postoperative dissection of the specimens was performed utilizing a detailed checklist and global rating scale to evaluate the completeness of release as well as presence of neurologic injury. Performance of residents was compared. Rho correlation analysis was used to verify validity of the assessment tools. Training year most strongly correlated with Global Rating Scale assessment values. There was a trend correlating training year with faster surgical times, and Detailed Checklist scores. Validation measurements showed strong correlations between the pass/fail grade and the Detailed Checklist and the Global Rating Scale. Complete release of the ulnar nerve in situ utilizing lighted retractors can be performed with minimal training or experience. (Journal of Surgical Orthopaedic Advances 32(3):193-198, 2023).
Subject(s)
Orthopedics , Plastic Surgery Procedures , Humans , Operative Time , Postoperative Period , CadaverABSTRACT
PURPOSE: To determine whether unilateral external fixation using a staged multiplanar reduction technique restores anatomic volar tilt in a distal radius fracture model. METHODS: We used radiographic images to obtain baseline measurements in 20 fresh-frozen cadaveric wrists. Through a standard dorsal approach to the radius, we performed osteotomies to simulate displaced AO/ASIF type C2 fractures. After placement of a unilateral external fixator, a stepwise technique of applying longitudinal traction followed by a volar translational maneuver was performed. Radiographic imaging was obtained after each step of the multiplanar reduction technique. RESULTS: Standard longitudinal traction did not restore volar tilt angles to their baseline measurements. The addition of a volar translation maneuver had a significant effect on restoring baseline volar tilt. There was a statistically significant difference in volar tilt measurements between straight longitudinal traction and volar translation. Radial inclination, radial height, and ulnar variance did not differ significantly between longitudinal traction and the addition of volar translation. CONCLUSIONS: A criticism of traditional external fixation is the inability of longitudinal ligamentotaxis to attain sagittal plane (volar tilt) reduction of the articular surface. This study demonstrates that a multiplanar reduction technique using unilateral external fixation devices on cadaveric distal radius fractures can achieve an acceptable reduction. CLINICAL RELEVANCE: External fixation of distal radius fractures may be favorable in situations where soft tissue loss, wound contamination, and comorbid medical factors preclude the use of internal fixation techniques. A multiplanar reduction technique using a unilateral external fixation device may facilitate fracture reduction in acceptable alignment.
Subject(s)
External Fixators , Fracture Fixation/instrumentation , Intra-Articular Fractures/surgery , Palmar Plate , Radius Fractures/surgery , Aged , Aged, 80 and over , Cadaver , Female , Humans , Male , Middle AgedABSTRACT
PURPOSE: To assess whether or not attempted closed reduction of fifth metacarpal neck fractures results in decreased fracture angulation at final follow-up. METHODS: Retrospective chart review of all patients aged 18 and older managed for isolated fifth metacarpal neck fractures between 2004 and 2014. RESULTS: Sixty-six patients managed for an isolated boxer fracture met inclusion criteria. Twenty-three patients underwent attempted reduction and 43 patients did not. Patients undergoing attempted reduction had a statistically significant improvement in fracture angulation following reduction compared with patients not undergoing attempted reduction. At final follow-up, there was no difference in fracture angle between the 2 groups. CONCLUSIONS: Closed reduction and splint immobilization of fifth metacarpal neck fractures was not an effective means of maintaining a significant improvement in fracture alignment upon healing. Other means, such as closed reduction with pin fixation or open reduction internal fixation, should be considered when maintenance of reduction is desired. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic III.
Subject(s)
Fracture Fixation, Internal , Fractures, Bone/surgery , Hand Deformities, Acquired/prevention & control , Metacarpal Bones/injuries , Adult , Female , Follow-Up Studies , Fracture Healing , Humans , Male , Retrospective Studies , Splints , Treatment OutcomeABSTRACT
STUDY DESIGN: Randomized clinical trial. PURPOSE: Contribution of the posterior interosseous nerve (PIN) and surrounding skin envelope to wrist proprioception is a topic of debate and the primary focus of this research. METHODS: We performed a double-blinded, placebo control study in which subjects underwent baseline multiplanar testing of wrist proprioception. They were randomized to receive either anesthetic blockade of the PIN within the fourth dorsal compartment, or circumferential topical anesthetic blockade of skin surrounding the wrist. Corresponding opposite wrists underwent placebo intervention with saline injection or inert ultrasound gel. Subjects repeated proprioceptive testing. RESULTS: Eighty subjects, 45 male and 35 female, mean age 33 years (range, 19-64 years), completed testing. The percentage of measurements falling outside a ±18° range did not differ between pre-treatment and post-treatment PIN blockade or for circumferential skin anesthesia. CONCLUSIONS: Wrist proprioception appears to be a multifactorial phenomenon. Surgeons may sacrifice the PIN without concern for effect on joint proprioception. LEVEL OF EVIDENCE: Level I.
Subject(s)
Brachial Plexus Block , Proprioception/physiology , Skin/innervation , Wrist Joint/innervation , Wrist Joint/physiology , Administration, Topical , Adult , Anesthetics, Local/administration & dosage , Double-Blind Method , Female , Humans , Injections, Subcutaneous , Lidocaine/administration & dosage , Logistic Models , Male , Middle Aged , Ointments , Prospective Studies , Young AdultABSTRACT
CASE: A 41-year-old male presented with an insidious onset of pain and swelling about the dorsal wrist, and was found to have a Brodie's abscess in the distal radius. The patient had a history of a distal radius fracture, treated with external fixation, nineteen years prior, which we believe contributed to the infection. The patient was treated surgically with abscess irrigation, debridement, bony curettage, bioactive glass S53P4 allograft, with concurrent antibiotic therapy. CONCLUSION: Brodie's abscesses can have atypical presentations, and a thorough history must be obtained from patients to identify any potential sources of infection.
Subject(s)
Abscess , Radius Fractures , Humans , Male , Adult , Radius Fractures/surgery , Abscess/etiology , Abscess/surgery , Abscess/microbiology , Debridement , Fracture Fixation/adverse effects , External Fixators , Anti-Bacterial Agents/therapeutic use , Osteomyelitis/etiology , Osteomyelitis/surgeryABSTRACT
CASE: Anterior interosseous nerve (AIN) palsy is an uncommon, though well-described, clinical entity. When isolated to the thumb, it can be confused with atraumatic rupture of the flexor pollicis longus (FPL) tendon. A 57-year-old man experienced atraumatic onset of difficulty flexing the distal interphalangeal thumb joint. Magnetic resonance imaging (MRI) demonstrated denervation edema of the FPL, suggesting atypical AIN palsy. Resolution of symptoms and MRI findings occurred concomitantly with nonoperative treatment. CONCLUSION: Atypical AIN palsy limited to the FPL is a rare clinical entity whose diagnosis can be supported with MRI. Here, we report a successful case of nonoperative management.
Subject(s)
Magnetic Resonance Imaging , Humans , Male , Middle Aged , Thumb/innervation , Thumb/diagnostic imagingABSTRACT
PURPOSE: The reasons for variation in the reported incidence rates between thumb metacarpophalangeal joint radial collateral ligament (RCL) and ulnar collateral ligament (UCL) injuries are unclear. Delay in diagnosis of injury to the RCL leads to greater time of patient disability. The purpose of this study was to define the demographics and presentation of patients with RCL injuries in a military health care system. METHODS: We performed a retrospective review of electronic medical records over a 5-year period to determine the incidence and epidemiology related to patients with instability of the thumb metacarpophalangeal joint resulting from injury of the radial or ulnar collateral ligaments. RESULTS: A total of 56 patients presented with thumb metacarpophalangeal joint instability. Of these, 18 (32%) had an RCL injury. Patients with an RCL injury were, on average, younger than those with UCL injuries. Those with RCL injuries were more likely to require surgery than were those with UCL injuries (67% vs 40%). With regard to time to presentation, most patients with UCL injuries presented 2 to 10 weeks after injury, whereas nearly all patients with RCL injuries presented greater than 10 weeks after injury. Radial collateral ligament injuries were more likely than UCL injuries to have resulted from an axial load (56% vs 16%), whereas UCL injuries were more likely to have been caused by an abduction-adduction moment (50% vs 22%). CONCLUSIONS: In this series, patients sustaining injuries to the RCL were younger and presented later than their counterparts with UCL instability. Close attention to subtle or frank instability presenting as pain in younger patients with axial loading injury mechanisms may allow early diagnosis and appropriate treatment of this injury.
Subject(s)
Collateral Ligaments/injuries , Finger Injuries/epidemiology , Metacarpophalangeal Joint/injuries , Military Personnel/statistics & numerical data , Thumb/injuries , Adult , Age Distribution , Cohort Studies , Collateral Ligaments/surgery , Female , Finger Injuries/diagnostic imaging , Finger Injuries/surgery , Follow-Up Studies , Humans , Incidence , Joint Instability/diagnostic imaging , Joint Instability/epidemiology , Male , Metacarpophalangeal Joint/diagnostic imaging , Metacarpophalangeal Joint/surgery , Middle Aged , Orthopedic Procedures/methods , Radiography , Range of Motion, Articular/physiology , Recovery of Function , Retrospective Studies , Risk Assessment , Sex Distribution , Thumb/diagnostic imaging , Thumb/surgery , Treatment Outcome , Young AdultABSTRACT
CASE: A 23-year-old elite-level gymnast presented with insidious-onset pain near the base of the second metacarpal. The patient was found to have a trapezoid stress fracture and was treated nonoperatively in a thumb spica cast for 4 weeks. He resumed gymnastics without limitations 8 weeks from the time of diagnosis. CONCLUSION: Trapezoid stress fractures must be considered when evaluating patients presenting with pain about the base of the index finger metacarpal, particularly those who perform activities that repetitively place high loads across the wrist. Wrist immobilization and a supervised return to participation resulted in an excellent outcome for this patient.
Subject(s)
Fractures, Stress , Male , Humans , Young Adult , Adult , Fractures, Stress/diagnostic imaging , Fractures, Stress/therapy , Wrist , Wrist Joint , Thumb , PainABSTRACT
BACKGROUND: Carpal tunnel release (CTR) is one of the most common hand surgeries. Studies have highlighted a mental-physical connection to hand pathologies and psychological connections to postoperative pain burden. Post-traumatic stress disorder (PTSD) has been identified as a medical-psychological comorbidity like other mental health disorders such as generalized anxiety disorder (GAD). There remains a gap in the literature regarding PTSD as a comorbidity for hand surgeries, where there is this mental-physical connection. We hypothesize PTSD will be associated with increased risk of postoperative pain, evidenced by greater prevalence of opioid usage. METHODS: The authors performed a retrospective analysis using the TriNetX Research Database. Patients who underwent elective CTR were identified within the database. Two groups were created and compared against individual controls: the first was identified based on the diagnosis of PTSD, and the second was identified based on the diagnosis of GAD. Cohorts were matched and opioid usage was compared postoperatively. RESULTS: Patients with PTSD who underwent CTR were found to be at significantly increased risk of postoperative opioid use (P = .033) and more likely to present to the emergency department (ED) (P = .001). Patients with GAD were found to be significantly less likely to require postoperative opioids (P = .040). CONCLUSIONS: We found patients with PTSD to be at increased risk of opioid use and more likely to present to ED following CTR. Patients with GAD were found to be at decreased risk of opioid use after CTR. Owing to the independent significant risks not found in GAD, further research of postoperative pain in patients with PTSD is needed.
ABSTRACT
CASE: A 58-year-old woman with a history of systemic sarcoidosis, 2 years in remission, presented 6 years after bilateral carpal tunnel release with a 3-month history of nodularity, erythema, and tenderness to her bilateral incisions. Histopathology demonstrated noncaseating granulomas without evidence of foreign material or organisms, consistent with infiltrative scar sarcoidosis. Treatment included 4 intralesional corticosteroid injections over 5 months, with progressive resolution of symptoms and no evidence of systemic sarcoidosis reoccurrence. CONCLUSION: Sarcoidosis should be considered when presented with a cutaneous lesion in association with an incisional scar, either as primary presentation or as disease recurrence.
Subject(s)
Carpal Tunnel Syndrome , Foreign Bodies , Sarcoidosis , Female , Humans , Middle Aged , Cicatrix/complications , Cicatrix/pathology , Sarcoidosis/complications , Sarcoidosis/diagnosis , Sarcoidosis/pathology , Carpal Tunnel Syndrome/surgery , Foreign Bodies/complications , Injections, IntralesionalABSTRACT
Finger amputations are commonly encountered. These may be revised in the emergency department (ED) or the operating room (OR). Previous studies have demonstrated the cost-effectiveness associated with procedures performed in the ED. Patient outcomes have not been described. We retrospectively reviewed patients who presented to our level 1 trauma center with a traumatic partial or complete finger amputation through flexor tendon zone I. All were treated with revision amputation performed in either the ED or the OR between January 2012 and December 2017. A total of 172 patient charts were included. Ninety-three of the revision amputations were performed in the ED, while 79 were performed in the OR. There was no difference in age, race, sex, having a manual labor job, medical comorbidities, or mechanism of injury between the groups. Compared with procedures performed in the ED, procedures performed in the OR had a higher rate of delayed healing, a longer stay in the hospital, and a higher referral to therapy postoperatively. Length of follow-up and number of follow-up visits were not statistically different based on location of procedure. There was no difference in post-procedural infection rate or need for revision procedure between the groups. Our data support the efficacy of performing revision amputation procedures in the ED. Recorded patient complications and subsequent treatment after revision amputations performed in the ED vs the OR were comparable. Those performed in the ED potentially decrease the burden placed on the patient and the health care system. [Orthopedics. 202x;4x(x):xx-xx.].
ABSTRACT
BACKGROUND: Patients with long-standing carpal tunnel symptoms may develop transient and, paradoxically, worsened neuropathic pain immediately following release. The authors have termed this "reawakening phenomenon." The purpose of this study was to compare the characteristics of patients with this phenomenon to those with a standard postoperative course. METHODS: A retrospective chart review was performed on all patients who underwent carpal tunnel release at a single institution between January of 2012 to December of 2017. Patients demonstrating increased neuropathic pain in the median nerve distribution postoperatively without evidence of complex regional pain syndrome were included. A comparison cohort was composed of the remaining patients identified. Demographic data, medical history, carpal tunnel history, and electromyogram and nerve conduction study findings were recorded. RESULTS: A total of 640 patients were identified; 440 met criteria. Seventeen patients were found to have symptoms consistent with median nerve reawakening phenomenon. The reawakening cohort was older (71.1 versus 56.8 years), more likely to have evidence of thenar muscle atrophy (58.8 percent versus 13.48 percent), and more likely to have fibrillations and sharp waves on electrodiagnostic studies. Although not statistically significant, they also had a longer duration of symptoms (4.9 versus 2.9 years). Of those patients with reawakening phenomenon, 14 had resolution of their symptoms at an average period of 4.4 months. Three remaining patients who were subjectively symptomatic had normal or improved postoperative electromyogram and nerve conduction studies. CONCLUSIONS: Reawakening of the median nerve has not been previously described but occurs in 3.9 percent of hands following routine carpal tunnel release. Preoperative counseling of patients at high risk for reawakening phenomenon is recommended. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.
Subject(s)
Carpal Tunnel Syndrome , Neuralgia , Neuritis , Carpal Tunnel Syndrome/diagnosis , Carpal Tunnel Syndrome/surgery , Humans , Median Nerve , Retrospective StudiesABSTRACT
Background: Many techniques for injection of trigger fingers exist. The purpose of this study was to determine whether the type of steroid or technique used for trigger finger injection altered clinical outcomes. Methods: Six hand surgeons at a single institution were surveyed regarding their injection technique, preferred steroid used, and protocol for repeat injection or indication for surgery for symptomatic trigger finger. A retrospective chart review of patients who underwent trigger finger injections was performed by randomly selecting 35 patients for each surgeon between January 2013 and December 2015. Demographic data at the time of presentation were collected. Outcome data during follow-up appointments were also recorded. Results: A total of 210 patient charts were reviewed. Demographic data and initial presenting grade of triggering were similar among all groups. There was no significant difference in clinical course or eventual outcomes noted with injection technique. There were 70 patients in each steroid cohort. Patients receiving triamcinolone required additional injections compared with those receiving methylprednisolone and dexamethasone. Eventual surgical intervention was significantly higher in those patients receiving methylprednisolone. The methylprednisolone group also underwent operative release significantly earlier. Conclusions: Trigger finger injections with triamcinolone demonstrate a higher rate of additional injections when compared with dexamethasone and methylprednisolone. Patients who underwent methylprednisolone injection had surgical release performed earlier and more frequently than the other 2 groups. The choice of corticosteroid significantly affected clinical outcome in this study population. Clinicians performing steroid injections for trigger finger may wish to consider these results when selecting a specific agent.
Subject(s)
Trigger Finger Disorder , Adrenal Cortex Hormones/therapeutic use , Humans , Injections , Retrospective Studies , Treatment Outcome , Trigger Finger Disorder/drug therapy , Trigger Finger Disorder/surgeryABSTRACT
Background: The purpose of the study was to determine the biomechanical effect of distal pin configuration in unilateral external fixation of distal radius fracture in a cadaveric model. Methods: A standardized 2-part extra-articular distal radius fracture model with dorsal comminution was created in 6 matched pairs of cadaveric upper extremities. Specimens within each matched pair were randomly assigned to either 4 or 6 cortices of distal pin metacarpal fixation. Cyclic, compressive loads were applied to the palmar hand. Results: No significant differences were detected in maximum forces. Six-cortex metacarpal fixation showed significantly lower magnitude of actuator displacement at 100 N cyclic loading. The difference in construct stiffness did not translate to disparities in angular and translational interfragmentary displacement at the fracture gap. Conclusions: Utilizing only 4 cortices and sparing the middle finger metacarpal avoids the need for a more transverse orientation required with 6-cortex fixation, which may otherwise impede thumb motion.
Subject(s)
Metacarpal Bones , Radius Fractures , Biomechanical Phenomena , Bone Plates , Cadaver , Humans , Metacarpal Bones/surgery , Radius Fractures/surgeryABSTRACT
OBJECTIVE: To determine if the addition of a dorsal ulnar pin plate provides improved stability characteristics in the management of intra-articular distal radius fractures with an associated dorsal ulnar fragment. METHODS: OTA/AO type C3 fractures, with a dorsal ulnar fragment of one-third or one-half the width of the distal radius, were simulated in 9 matched pairs of fresh-frozen cadaveric arms randomized between fixed-angle volar plate only versus volar plate with addition of a dorsal ulnar pin plate. Prepared specimens were mounted in a custom load frame and loaded in extension with stepwise cyclic load increase. Dorsal plane interfragmentary displacements were compared between the 2 fixation constructs at 50-N and 100-N cyclic load. RESULTS: The addition of the dorsal ulnar pin plate significantly reduced interfragmentary displacements for the dorsal ulnar fragment at the 50 N load application, resulting in mean interfragmentary displacements of -0.1 ± 0.2 mm in comparison to -0.3 ± 0.2 mm with the volar plate-only construct. No other interfragmentary displacement comparisons were significant. No differences were found comparing the one-third and one-half size fragments. CONCLUSIONS: The addition of a dorsal ulnar pin plate improved stability characteristics with respect to the dorsal ulnar fragment. CLINICAL RELEVANCE: The addition of the dorsal ulnar pin plate, although statistically significant, improved displacement by less than 0.3 mm on average and thus may not prove to be important in clinical scenarios.
Subject(s)
Bone Plates , Radius Fractures , Radius , Biomechanical Phenomena , Cadaver , Fracture Fixation, Internal , Humans , Radius Fractures/surgeryABSTRACT
Osteoid osteomas are benign, typically intracortical lesions most often affecting the diaphyses of long bones. We describe a case involving a 26-year-old male laborer who presented with the insidious onset of ulnar-sided wrist pain. He was diagnosed with and successfully treated with surgical excision for an osteoid osteoma involving the hook of the hamate.
ABSTRACT
PURPOSE: To evaluate variables unique to our military population to determine whether we can be better predict functional outcome and return to duty of active duty military soldiers with multiligament knee disruption following arthroscopically assisted reconstruction. MATERIALS AND METHODS: Twenty-four active duty Army personnel who underwent arthroscopically assisted reconstruction of multiple ligament disruption by the same surgeon were enrolled in this study. Postoperatively, a standardized knee joint questionnaire was administered and current vocational and recreational status was evaluated. Demographic data as well as military-specific factors to include rank, military occupation specialty, associated injuries, and retention on active duty were reviewed for these patients to determine their correlation with outcome. RESULTS: Overall, 13 (54%) remained on active duty following surgical reconstruction of their knee. There was a positive correlation between military rank and return to military duty. We were unable to correlate physical job demand to postinjury duty status. The Cincinnati Knee Ligament Rating Scale indicated that most soldiers were able to perform sports at "half speed", with "some limits" in daily living function scores. CONCLUSION: Arthroscopically assisted multiligament knee reconstruction enabled only a slight majority of active duty soldiers to return to duty following reconstruction and rehabilitation of this devastating injury.
Subject(s)
Arthroscopy/methods , Knee Injuries/surgery , Ligaments, Articular/surgery , Military Personnel , Adult , Female , Humans , Ligaments, Articular/injuries , Male , Middle Aged , Recovery of Function , Treatment OutcomeABSTRACT
In this retrospective study, we report the preliminary results of a novel technique for volar vascularized strut grafting to treat avascular scaphoid nonunion by using the 1,2 intercompartmental supraretinacular artery through a single incision. Forty-three of 45 patients with avascular scaphoid nonunion healed at a mean of 13 weeks (range, 3 to 10 mo). Complications consisted of 1 pin tract infection that resolved with oral antibiotics and 4 cases of transient dysesthesia of the radial sensory nerve. In 4 patients with equivocal radiographs, computed tomography scans confirmed bony union. The 2 patients who remained unhealed subsequently underwent proximal row carpectomy. Two other patients had persistent pain with the progression of radiocarpal arthritis. Our technique provides good results for the treatment of avascular scaphoid fracture nonunion. Notable advantages include performance through a single incision, use of an already established vascularized bone graft, volar graft placement, and no requirement for microvascular free graft reconstruction. It also provides the surgeon with the ability to adjust the procedure intraoperatively in the event of unexpected avascularity, without requiring substantially longer operative time or additional equipment.