Outcome Analysis of External Neurolysis in Posture-Induced Compressive Peroneal Neuropathy and the Utility of Magnetic Resonance Imaging in the Treatment Process.

OBJECTIVE: We aimed to analyze the effectiveness of external neurolysis on the common peroneal nerve (CPN) in patients with posture-induced compressive peroneal neuropathy (PICPNe). Further, we aimed to examine the utility of magnetic resonance imaging (MRI) in assessing the severity of denervation status and predicting the postoperative prognosis. METHODS: We included 13 patients (eight males and five females) with foot drop who underwent CPN decompression between 2018 and 2020. We designed a grading system for assessing the postoperative functional outcome. Additionally, we performed MRI to evaluate the denervation status of the affected musculature and its effect on postoperative recovery. RESULTS: The median time to surgery was 3 months. The median preoperative ankle dorsiflexion and eversion grades were both 3, while the average functional grade was 1. Posterior crural intermuscular septum was the most common cause of nerve compression, followed by deep tendinous fascia and anterior crural intermuscular septum. There was a significant postoperative improvement in the median postoperative ankle dorsiflexion and eversion grades and average postoperative functional (4, 5, and 2.38, respectively). Preoperative ankle eversion was significantly correlated with denervation status. Additionally, the devernation status on MRI was positively correlated with the outcome favorability. However, denervation atrophy led to a less favorable outcome. CONCLUSION: Among patients with intractable PICPNe despite conservative management, surgical intervention could clinically improve motor function and functional ability. Additionally, MRI examination of the affected muscle could help diagnose CPNe and assess the postoperative prognosis.

Diagnostic Roots Radiofrequency Sensory Stimulation Looking for Symptomatic Injured Roots in Multiple Lumbar Stenosis.

Objective: We present how to perform radiofrequency sensory stimulation (RFSS) and whether RFSS could be helpful in identifying symptomatic injured roots in multilevel lumbar stenosis. Methods: Consecutive patients who underwent RFSS from 2010 to 2012 were enrolled. To identify pathologic lesions, RFSS was performed for suspicious roots, as determined using lumbar magnetic resonance imaging (MRI). The RFSS procedure resembled transforaminal root block. During RFSS of the suspicious root, patients could indicate whether stimulation induced their usual pain and/or sensory changes and could indicate whether the same leg area was affected. The number of possible symptomatic roots on MRI was evaluated before and after RFSS. Based on the RFSS results, we confirmed the presence of symptomatic nerve root(s) and performed surgical decompression. Surgical results, such as numeric rating scale (NRS) scores for low back pain (LBP) and leg pain (LP), and Oswestry disability index (ODI), were evaluated. Results: Ten patients were enrolled in the study. Their mean age was 70.1±9.7 years. Clinically, NRS-LBP, NRS-LP, and ODI before surgery were 5.1%, 7.5%, and 53.2%, respectively. The mean number of suspicious roots was 2.6±0.8. After RFSS, the mean number of symptomatic roots was 1.6±1.0. On average, 1.4 lumbar segments were decompressed. The follow-up period was 35.3±12.8 months. At the last follow-up, NRS-LBP, NRS-LP, and ODI were 3.1%, 1.5%, and 35.3%, respectively. There was no recurrence or need for further surgical treatment for lumbar stenosis. Conclusion: RFSS is a potentially helpful diagnostic tool for verifying and localizing symptomatic injured root lesions, particularly in patients with multilevel spinal stenosis.

Removal of malformation in cerebral proliferative angiopathy: illustrative case.

BACKGROUND: Cerebral proliferative angiopathy (CPA) is a rare vascular disorder distinct from arteriovenous malformation. Because of the disorder's rarity, there is still a controversy on the most promising treatment method for CPA. However, several meta-analysis articles suggest indirect vascularization such as encephalo-duro-arterio-synangiosis as an effective way of treating symptoms that are medically uncontrolled. OBSERVATIONS: The authors describe a case of an 11-year-old boy with this disease, who had epilepsy that was intractable despite conservative management. The patient recovered from his symptoms after the vascular malformation was surgically removed. This is the first reported case of surgical removal in CPA. LESSONS: Although further investigation on the best treatment for CPA is needed, the authors believe surgical intervention may also be an effective treatment modality when a patient presents with persisting symptoms.

A Prospective Observational Study of Return to Work after Single Level Lumbar Discectomy.

OBJECTIVE: Lumbar disc herniation (LDH) is a common disease, and lumbar discectomy (LD) is a common neurosurgical procedure. However, there is little previous data on return to work (RTW) after LD. This study investigated the period until the RTW after LD prospectively. Clinically, the pain state at the time of RTW also checked. RTW failure rate 6 months after surgery also investigated. METHODS: Patients with daily/regular jobs undergoing LD between September 2014 and December 2018 were enrolled. Pain was assessed by the Oswestri Disability Index (ODI) and the Numeric Rate Scale (NRS). Employment type was divided into self-employed, regular and contracted. Monthly telephone interviews were conducted to check RTW status and self-estimated work capability after surgery. RESULTS: Sixty-seven patients enrolled in this study. Three patients failed to RTW, and three others resigned within 6 months after surgery. The preoperative NRS and ODI were 7.2±1.2 and 22.1±7.9, respectively. The average time to RTW was 5.1±6.0 weeks. At RTW, NRS was 1.5±1.8 and ODI was 6.3±3.9. Amongst patients that successfully returned to work were 16 self-employed workers, 42 regular employees, and three contracted workers. The time to RTW of self-employed, regular, and contracted workers were 5.9±8.8, 4.2±4.3 and 13.3±2.3 weeks, respectively (p=0.011). Thirty-six of the patients that returned to work self-reported a 22.8±15.6% reduction in work capability at 6 months. CONCLUSION: RTW may vary depending on the employment status. In this study, we found that while employment type may affect the length to RTW, most patients were able to RTW and >40% of patients reported no loss of work capabilities 6 months postoperatively, hopefully alleviating some patient hesitation towards LD.

Retrospective Chronologic Computed Tomography Analysis of Bone Flap Fusion and Resorption After Craniotomy and Autologous Cryopreserved Cranioplasty.

BACKGROUND: In open brain surgery, fixation of the bone flap is the final procedure. The bone flaps then fuse naturally. The objective of this study was to investigate the chronological process of bone fusion after craniotomy and autologous cranioplasty. METHODS: Retrospective data were collected from patients who underwent craniotomy or cranioplasty after August 2004 and had at least 1 computed tomography (CT) scan at 3 months postsurgery. The patients were divided into a craniotomy group and a cranioplasty group. Head CT scans were analyzed to evaluate bone fusion and resorption. RESULTS: Records from 978 patients who underwent craniotomy or cranioplasty between September 2004 and November 2015 were reviewed; 369 patients were eligible for the final analysis (craniotomy, n = 276; cranioplasty, n = 93). The mean cryopreservation period for the bone flap in the cranioplasty group was 49.3 days. The mean patient age was 51.4 ± 18.1 years in the craniotomy group and 51.6 ± 17.1 years in the cranioplasty group. Head CT scans showed bone fusion rates of 76.6% in the craniotomy group and 53.3% in the cranioplasty group at 6 months postsurgery (P = 0.015) and 78.6% and 78.1%, respectively, at 1 year postsurgery (P = 0.951). There was also a significant difference in the bone flap resorption rate between the 2 groups. CONCLUSIONS: Bone flap fusion rates after craniotomy and cranioplasty were significantly different before 12 months, but not significantly different thereafter. Bone resorption occurred more frequently in the cranioplasty group over time.

Factors Associated With Longer Postoperative Outpatient Follow-up Duration in Patients With Single Lumbar Disc Herniation: A Noncomplicated Patient Cohort Study.

OBJECTIVE: Many reports have described the outcomes of surgical treatment of lumbar disc herniation (LDH). However, few reports have investigated the treatment period after lumbar disc surgery. If no complications occur, how long should an ordinary patient be treated? Which factors are associated with the outpatient follow-up period (OFP)? To answer these questions, we reviewed the medical records of patients who underwent lumbar disc surgery, calculated their average OFP, and sought to identify factors associated with the OFP. METHODS: Patients who underwent surgical treatment of single-level LDH from July 2005 to December 2011 were enrolled in this study. Patients who had no pain or required no further treatment did not receive follow-up. Patients' medical records were reviewed retrospectively. Cases of recurrent LDH, postoperative infections, instrumentation, cauda equina syndrome, postoperative hematoma, trauma-associated herniation, and spondylolisthesis were excluded. We reviewed the postoperative hospitalization period (PHP) and the OFP. Sex, age, operation year, surgical approach, the operating surgeon, disc level, and insurance type were investigated as associated factors. RESULTS: In total, 611 patients underwent surgical treatment for single-level LDH by 4 surgeons. Their average age was 44.3 ± 15.1 years. There were 377 male and 234 female patients. The average PHP was 4.4 ± 3.2 days, the average OFP was 112.3 ± 198.6 days, and the 95% confidence interval for the OFP among the enrolled patients was between 96.5 and 128.1 days. CONCLUSION: Although this is a single-institute report, most LDH patients showed an OFP of less than 4 months after surgical treatment. In this study, sex, age, and insurance type seemed to be related with the OFP.

Anatomical Variants of "Short Head of Biceps Femoris Muscle" Associated with Common Peroneal Neuropathy in Korean Populations : An MRI Based Study.

OBJECTIVE: In Asians, kneeling and squatting are the postures that are most often induce common peroneal neuropathy. However, we could not identify a compatible compression site of the common peroneal nerve (CPN) during hyper-flexion of knees. To evaluate the course of the CPN at the popliteal area related with compressive neuropathy using magnetic resonance imaging (MRI) scans of healthy Koreans. METHODS: 1.5-Tesla knee MRI scans were obtained from enrolled patients and were retrospectively reviewed. The normal populations were divided into two groups according to the anatomical course of the CPN. Type I included subjects with the CPN situated superficial to the lateral gastocnemius muscle (LGCM). Type II included subjects with the CPN between the short head of biceps femoris muscle (SHBFM) and the LGCM. We calculated the thickness of the SHBFM and posterior elongation of this muscle, and the LGCM at the level of femoral condyles. In type II, the length of popliteal tunnel where the CPN passes was measured. RESULTS: The 93 normal subjects were included in this study. The CPN passed through the "popliteal tunnel" formed between the SHBFM and the LGCM in 36 subjects (38.7% type II). The thicknesses of SHBFM and posterior portions of this muscle were statistically significantly increased in type II subjects. The LGCM thickness was comparable in both groups. In 78.8% of the "popliteal tunnel", a length of 21 mm to <40 mm was measured. CONCLUSION: In Korean population, the course of the CPN through the "popliteal tunnel" was about 40%, which is higher than the Western results. This anatomical characteristic may be helpful for understanding the mechanism of the CPNe by posture.

Pullout strength after expandable polymethylmethacrylate transpedicular screw augmentation for pedicle screw loosening.

OBJECTIVE: Pedicle screw fixation for spine arthrodesis is a useful procedure for the treatment of spinal disorders. However, instrument failure often occurs, and pedicle screw loosening is the initial step of a range of complications. The authors recently used a modified transpedicular polymethylmethacrylate (PMMA) screw augmentation technique to overcome pedicle screw loosening. Here, they report on the laboratory testing of pedicle screws inserted using this modified technique. METHODS: To evaluate pullout strengths three cadaveric spinal columns were used. Three pedicle screw insertion methods were utilized to compare pullout strength; the three methods used were; control (C), traditional transpedicular PMMA augmentation technique (T), and the modified transpedicular augmentation technique (M). After control screws had been pulled out, loosening with instrument was made. Screw augmentations were executed and screw pullout strength was rechecked. RESULTS: Pedicle screws augmented using the modified technique for pedicle screw loosening had higher pullout strengths than the control (1106.2±458.0 N vs. 741.2±269.5 N; p=0.001). Traditional transpedicular augmentation achieved a mean pullout strength similar to that of the control group (657.5±172.3 N vs. 724.5±234.4 N; p=0.537). The modified technique had higher strength than the traditional PMMA augmentation technique (1070.8±358.6 N vs. 652.2±185.5 N; p=0.023). CONCLUSION: The modified PMMA transpedicular screw augmentation technique is a straightforward, effective surgical procedure for treating pedicle screw loosening, and exhibits greater pullout strength than traditional PMMA transpedicular augmentation. However, long-term clinical evaluation is required.

Clinical characteristics of peroneal nerve palsy by posture.

OBJECTIVE: Posture induced common peroneal nerve (CPN) palsy is usually produced during the prolonged squatting or habitual leg crossing while seated, especially in Asian culture and is manifested by the onset of foot drop. Because of its similarity to discogenic foot drop, patients may be diagnosed with a lumbar disc disorder, and in some patients, surgeons may perform unnecessary examinations and even spine surgery. The purpose of our study is to establish the clinical characteristics and diagnostic assessment of posture induced CPN palsy. METHODS: From June 2008 to June 2012, a retrospective study was performed on 26 patients diagnosed with peroneal nerve palsy in neurophysiologic study among patients experiencing foot drop after maintaining a certain posture for a long time. RESULTS: The inducing postures were squatting (14 patients), sitting cross-legged (6 patients), lying down (4 patients), walking and driving. The mean prolonged neural injury time was 124.2 minutes. The most common clinical presentation was foot drop and the most affected sensory area was dorsum of the foot with tingling sensation (14 patients), numbness (8 patients), and burning sensation (4 patients). The clinical improvement began after a mean 6 weeks, which is not related to neural injury times. Electrophysiology evaluation was performed after 2 weeks later and showed delayed CPN nerve conduction study (NCS) in 24 patients and deep peroneal nerve in 2 patients. CONCLUSION: We suggest that an awareness of these clinical characteristics and diagnostic assessment methods may help clinicians make a diagnosis of posture induced CPN palsy and preclude unnecessary studies or inappropriate treatment in foot drop patients.

Epidural Hematoma Related with Low-Dose Aspirin : Complete Recovery without Surgical Treatment.

Hemorrhagic complications associated with aspirin use occur primarily at skin or gastrointestinal sites but can occasionally occur in the central nervous system. In particular, spontaneous spinal epidural hemorrhage (SSEH) associated with aspirin is very rare. We report a case of low-dose (100 mg daily) aspirin-related SSEH that was successfully treated with medical management. Our case indicates that low-dose aspirin could induce SSEH and that conservative treatment with close observation and repeated imaging studies should be considered in cases with neurological improvement or mild deficits.

Modified polymethylmethacrylate cervical plate and screw augmentation technique for intraoperative screw loosening.

STUDY DESIGN: Case report including technical note. OBJECTIVE: We describe 2 cases of intraoperative cervical plate screw loosening treated by modified screw augmentation using polymethylmethacrylate (PMMA), which used the anchoring effect of hardened PMMA. SUMMARY OF BACKGROUND DATA: Intraoperative screw loosening during cervical plating is not rare. PMMA augmentation for a damaged pilot hole is one of the rescue techniques in such a case. METHODS: A 52-year-old man who had complained of posterior neck pain and left arm pain underwent anterior cervical discectomy and plating with cage at the level of C6/7. An 82-year-old woman presenting bilateral arm weakness and radiating pain after trauma underwent the same operation at C5/6/7. Both of them showed intraoperative screw loosening, which was rectified by modified screw augmentation with PMMA. The difference between this technique and conventional PMMA augmentation is the anchoring effect of hardened PMMA. This technique does not need a new screw trajectory, but uses the existing dead space around the loosened screw. After filling the dead space with about 0.5 mL of PMMA, we inserted a small-sized screw. Once the PMMA hardened, we could remove the small screw and insert a thicker screw along the existing screw thread to increase the screws' pullout strength and achieve rigid fixation of plate. RESULTS: The condition of both patients improved without any instrument failure. In the first case, the visual analog scale and Neck Disability Index improved from 10 to 1 and from 64% to 2%, respectively. In the other patient, the visual analog scale and Neck Disability Index improved from 10 to 4 and from 66% to 40%, respectively. X-ray at 6-month follow-up showed no evidence of screw loosening. CONCLUSIONS: This modified PMMA augmentation is a simple, safe, and promising surgical technique to correct intraoperative screw loosening during cervical plating.

Single incision percutaneous pedicle screw fixation for transforaminal lumbar interbody fusion.

OBJECTIVE: Percutaneous pedicle screw fixation (PPSF) offers some of the advantages of minimally invasive surgery. However, an additional skin incision is necessary in order to gain these advantages. The author recently performed a modified PPSF through a single skin incision and it yielded good results. Here, we report the single incision percutaneous pedicle screw fixation (SIPPSF). METHODS: The medical records of 51 patients who underwent single segment transforaminal lumbar interbody fusion (TLIF) with pedicle screw fixation (PSF) between December 2009 and December 2011 were reviewed. The patients were divided into 3 groups according to the PSF technique used; conventional group (Group C), SIPPSF (Group S) and PPSF through multiple skin incisions (Group M). Operation time, estimated blood loss (EBL) and pain intensity before and after the operation using a numeric rating scale (NRS) were evaluated. RESULTS: The number of patients in Group S, Group C and Group M was 25, 17 and 9, respectively. The NRS demonstrated a reduction in pain intensity in all the patients, and there were no differences in NRS scoring between the three groups. Group S showed a reduction in the EBL compared to Group C (p=0.001) and a reduction in the operation time compared to Group M(p=0.003). CONCLUSION: The author supposes that the type of skin incision does not correlate significantly with the clinical results of TLIF with PPSF. However, it can be considered that SIPPSF offers the advantage of avoiding an additional paramedian skin incision.

Postoperative systemic dissemination of injected elemental mercury.

There were only a few reports of mercury on pulmonary artery. However, there is no data on surgery related mercury dissemination. The objective of the present article is to describe one case of postoperative injected mercury dissemination. A 19-year-old man presented severe neck pain including meningeal irritation sign and abdominal pain after injection of mercury for the purpose of suicide. Radiologic study showed injected mercury in the neck involving high cervical epidural space and subcutaneous layer of abdomen. Partial hemilaminectomy and open mercury evacuation of spinal canal was performed. For the removal of abdominal subcutaneous mercury, C-arm guided needle aspiration was done. After surgery, radiologic study showed disseminated mercury in the lung, heart, skull base and low spinal canal. Neck pain and abdominal pain were improved after surgery. During 1 month after surgery, there was no symptom of mercury intoxication except increased mercury concentration of urine, blood and hair. We assumed the bone work during surgery might have caused mercury dissemination. Therefore, we recommend minimal invasive surgical technique for removal of injected mercury. If open exposures are needed, cautious surgical technique to prohibit mercury dissemination is necessary and normal barrier should be protected to prevent the migration of mercury.

A case of pedicle screw loosening treated by modified transpedicular screw augmentation with polymethylmethacrylate.

We report a case of pedicle screw loosening treated by modified transpedicular screw augmentation technique using polymethylmethacrylate (PMMA), which used the anchoring effect of hardened PMMA. A 56-year-old man who had an L3/4/5 fusion operation 3 years ago complained of continuous low back pain after this operation. The computerized tomography showed a radiolucent halo around the pedicle screw at L5. We augmented the L5 pedicle screw with modified pedicle screw augmentation technique using PMMA and performed an L3/4/5 pedicle screw fixation without hook or operation field extension. This modified technique is a kind of transpedicular stiffness augmentation using PMMA for the dead space around the loosed screw. After filling the dead space with 1-2 cc of PMMA, we inserted a small screw. Once the PMMA hardened, we removed the small screw and inserted a thicker screw along the existing screw threading to improve the pedicle screws' pullout strength. At 10 months' follow-up, x-ray showed strong fusion of L3/4/5. The visual analogue scale (VAS) of his back pain was improved from 9 to 5. This modified transpedicular screw augmentation with PMMA using anchoring effect is a simple and effective surgical technique for pedicle screw loosening. However, clinical analyses of long-term follow-up and biomechanical studies are needed.

Spontaneous spinal epidural hematomas associated with acute myocardial infarction treatment.

Many studies have reported spontaneous spinal epidural hematoma (SSEH). Although most cases are idiopathic, several are associated with thrombolytic therapy or anticoagulants. We report a case of SSEH coincident with acute myocardial infarction (AMI), which caused serious neurological deficits. A 56 year old man presented with chest pain accompanied with back and neck pain, which was regarded as an atypical symptom of AMI. He was treated with nitroglycerin, aspirin, low molecular weight heparin, and clopidogrel. A spinal magnetic resonance image taken after paraplegia developed 3 days after the initial symptoms revealed an epidural hematoma at the cervical and thoracolumbar spine. Despite emergent decompressive surgery, paraplegia has not improved 7 months after surgery. A SSEH should be considered when patients complain of abrupt, strong, and non-traumatic back and neck pain, particularly if they have no spinal pain history.

A case of temporal intracerebral hemorrhage that presented with sudden bilateral hearing loss as the initial symptom.

A 57-year-old man presented to the outpatient department with sudden bilateral hearing loss. The otological examination suggested bilateral severe sensorineural hearing loss. After several hours, the patient complained of a headache and became drowsy. The brain computed tomography showed a 3 × 4 cm intracerebral hemorrhage (ICH) of the left temporal lobe. Surgery was performed and 34 days after the procedure the patient was discharged from the hospital with severe bilateral sensorineural hearing loss (SNHL). Temporal lobe ICH should be considered in the differential diagnosis of patients with sudden bilateral hearing loss, regardless of the other neurological symptoms.

Comparative study of lumbar magnetic resonance imaging and myelography in young soldiers with herniated lumbar disc.

OBJECTIVE: This study was undertaken to compare the diagnostic performances of magnetic resonance imaging (MRI), MR myelography (MRM) and myelography in young soldiers with a herniated lumbar disc (HLD). METHODS: Sixty-five male soldiers with HLD comprised the study cohort. A visual analogue scale for low back pain (VAS-LBP), VAS for leg radiating pain (VAS-LP), and Oswestry disability index (ODI) were applied. Lumbar MR, MRM, and myelographic findings were checked and evaluated by four independent radiologists, respectively. Each radiologist was asked to score (1 to 5) the degree of disc protrusion and nerve root compression using modified grading systems devised by the North American Spine Society and Pfirrmann and the physical examination rules for conscription in the Republic of Korea. Correlated coefficients between clinical and radiological factors were calculated. Interpretational reproducibility between MRI and myelography by four bases were calculated and compared. RESULTS: Mean patient age was 20.5 ± 1.1. Mean VAS-LBP and VAS-LP were 6.7 ± 1.6 and 7.4 ± 1.7, respectively. Mean ODI was 48.0 ± 16.2%. Mean MRI, MRM, and myelography scores were 3.3 ± 0.9, 3.5 ± 1.0, and 3.9 ± 1.1, respectively. All scores of diagnostic performances were significantly correlated (p < 0.05). However, none of these scores reflected the severity of patients' symptoms. There was no statistical difference of interpretational reproducibility between MRI and myelography. CONCLUSION: Although MRI and myelography are based on different principles, they produce similar interpretational reproducibility in young soldiers with a HLD. However, these modalities do not reflect the severity of symptoms.

Detection of traumatic cerebral microbleeds by susceptibility-weighted image of MRI.

OBJECTIVE: Susceptibility-weighted image (SWI) is a sensitive magnetic resonance image (MRI) technique to detect cerebral microbleeds (MBLs), which would not be detected by conventional MRI. We performed SWI to detect MBLs and investigated its usefulness in the evaluation of mild traumatic brain injury (MTBI) patients. METHODS: From December 2006 to June 2007, twenty-one MTBI patients without any parenchymal hemorrhage on conventional MRI were selected. Forty-two patients without trauma were selected for control group. According to the presence of MBLs, we divided the MTBI group into MBLs positive [SWI (+)] and negative [SWI (-)] group. Regional distribution of MBLs and clinical factors were compared between groups. RESULTS: Fifty-one MBLs appeared in 16 patients of SWI (+) group and 16 MBLs in 10 patients of control group [control (+)], respectively. In SWI (+) group, MBLs were located more frequently in white matters than in deep nucleus different from the control (+) group (p < 0.05). Nine patients (56.3%) of SWI (+) group had various neurological deficits (disorientation in 4, visual field defect in 2, hearing difficulty in 2 and Parkinson syndrome in 1). Initial Glasgow Coma Scale (GCS)/mean Glasgow Outcome Scale (GOS) were 13.9 +/- 1.5 / 4.7 +/- 0.8 and 15.0 +/- 0.0 / 5.0 +/- 0.0 in SWI (+) and SWI (-) groups, respectively (p < 0.05). CONCLUSION: Traumatic cerebral MBLs showed characteristic regional distribution, and seemed to have an importance on the initial neurological status and the prognosis. SWI is useful for detection of traumatic cerebral MBLs, and can provide etiologic evidences for some post-traumatic neurologic deficits which were unexplainable with conventional MRI.

The time course of range of motion loss after cervical laminoplasty: a prospective study with minimum two-year follow-up.

STUDY DESIGN: A prospective study. OBJECTIVE: To identify the time-dependent change in range of motion (ROM) after cervical laminoplasty. SUMMARY OF BACKGROUND DATA: Although numerous studies have reported on the loss of flexion/extension ROM associated with laminoplasty, few have reported on the time course of this loss of motion. METHODS: Twenty-three patients who received unilateral open-door laminoplasties, including miniplate fixation over 2 levels, were serially evaluated at regular set intervals after surgery. The mean follow-up period was 26.78 months (range: 24-41 months). Twelve patients had OPLL and 11 patients had cervical spondylotic myelopathy. Enrolled patients were divided into 2 groups (ossification of posterior longitudinal ligament [OPLL] and cervical spondylotic myelopathy) to compare the ROM between the OPLL and the spondylosis patients. We evaluated the time-dependent neck ROM changes by taking neutral, flexion, and extension radiographs before surgery and at 1, 3, 6, 9, 12, 18, and 24 months after surgery. Postoperative neck and arm pain was evaluated using a numerical rating scale. RESULTS: The preoperative, and 1-, 3-, 6-, 9-, 12-, 18-, and 24-month postoperative ROM figures were 37.8 degrees +/- 14.6 degrees, 34.1 degrees +/- 12.9 degrees, 35.0 degrees +/- 12.3 degrees, 30.3 degrees +/- 13.0 degrees, 28.6 degrees +/- 15.1 degrees, 27.3 degrees +/- 12.4 degrees, 26.1 degrees +/- 14.8 degrees, and 25.9 degrees +/- 13.2 degrees, respectively, and at the most recent follow-up, ROM was 25.8 +/- 15.2 degrees. Thus, the mean ROM decreased by 10.1 degrees +/- 9.5 degrees (31.66%) after surgery (P = 0.002). In OPLL group, we observed a more limited cervical ROM than in cervical spondylotic myelopathy group (35.3% vs. 29.2%). However, the rate of ROM reduction slowed with time in both groups (P = 0.000). Postoperative axial pain did not correlate with the degree of serial cervical ROM. CONCLUSION: The results suggest that the loss of cervical ROM is time-dependent and plateaus by 18 months after surgery, with no further decreases thereafter.